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TCSH(1)			    General Commands Manual		       TCSH(1)

NAME
       tcsh - C	shell with file	name completion	and command line editing

SYNOPSIS
       tcsh [-bcdefFimnqstvVxX]	[-Dname[=value]] [arg ...]
       tcsh -l

DESCRIPTION
       tcsh  is	 an enhanced but completely compatible version of the Berkeley
       UNIX C shell, csh(1).  It is a command language interpreter usable both
       as an interactive login shell and a shell script	command	processor.  It
       includes	a command-line editor (see The command-line editor),  program-
       mable word completion (see Completion and listing), spelling correction
       (see Spelling correction), a history mechanism (see  History  substitu-
       tion),  job  control  (see Jobs)	and a C-like syntax.  The NEW FEATURES
       section describes major enhancements of tcsh over  csh(1).   Throughout
       this  manual, features of tcsh not found	in most	csh(1) implementations
       (specifically, the 4.4BSD csh) are labeled  with	 `(+)',	 and  features
       which are present in csh(1) but not usually documented are labeled with
       `(u)'.

   Argument list processing
       If the first argument (argument 0) to the shell is `-' then it is a lo-
       gin  shell.   A login shell can be also specified by invoking the shell
       with the	-l flag	as the only argument.

       The rest	of the flag arguments are interpreted as follows:

       -b  Forces a ``break'' from  option  processing,	 causing  any  further
	   shell arguments to be treated as non-option arguments.  The remain-
	   ing arguments will not be interpreted as shell options.   This  may
	   be used to pass options to a	shell script without confusion or pos-
	   sible subterfuge.  The shell	will not  run  a  set-user  ID	script
	   without this	option.

       -c  Commands  are  read	from  the  following  argument	(which must be
	   present, and	must be	a single  argument),  stored  in  the  command
	   shell  variable  for	 reference, and	executed.  Any remaining argu-
	   ments are placed in the argv	shell variable.

       -d  The shell loads the directory stack from  ~/.cshdirs	 as  described
	   under Startup and shutdown, whether or not it is a login shell. (+)

       -Dname[=value]
	   Sets	the environment	variable name to value.	(Domain/OS only) (+)

       -e  The	shell  exits  if  any invoked command terminates abnormally or
	   yields a non-zero exit status.

       -f  The shell does not load any resource	or startup files,  or  perform
	   any command hashing,	and thus starts	faster.

       -F  The shell uses fork(2) instead of vfork(2) to spawn processes. (+)

       -i  The	shell is interactive and prompts for its top-level input, even
	   if it appears to not	be a terminal.	Shells are interactive without
	   this	option if their	inputs and outputs are terminals.

       -l  The shell is	a login	shell.	Applicable only	if -l is the only flag
	   specified.

       -m  The shell loads ~/.tcshrc even if it	does not belong	to the	effec-
	   tive	user.  Newer versions of su(1) can pass	-m to the shell. (+)

       -n  The	shell parses commands but does not execute them.  This aids in
	   debugging shell scripts.

       -q  The shell accepts SIGQUIT (see Signal handling) and behaves when it
	   is used under a debugger.  Job control is disabled. (u)

       -s  Command input is taken from the standard input.

       -t  The	shell reads and	executes a single line of input.  A `\'	may be
	   used	to escape the newline at the end of  this  line	 and  continue
	   onto	another	line.

       -v  Sets	 the  verbose  shell variable, so that command input is	echoed
	   after history substitution.

       -x  Sets	the echo shell variable, so that commands are  echoed  immedi-
	   ately before	execution.

       -V  Sets	the verbose shell variable even	before executing ~/.tcshrc.

       -X  Is to -x as -V is to	-v.

       --help
	   Print a help	message	on the standard	output and exit. (+)

       --version
	   Print the version/platform/compilation options on the standard out-
	   put and exit.  This information is also contained  in  the  version
	   shell variable. (+)

       After processing	of flag	arguments, if arguments	remain but none	of the
       -c, -i, -s, or -t options were given, the first argument	 is  taken  as
       the  name  of  a	 file of commands, or ``script'', to be	executed.  The
       shell opens this	file and saves its name	for possible resubstitution by
       `$0'.   Because	many systems use either	the standard version 6 or ver-
       sion 7 shells whose shell scripts are not compatible with  this	shell,
       the  shell uses such a `standard' shell to execute a script whose first
       character is not	a `#', i.e., that does not start with a	comment.

       Remaining arguments are placed in the argv shell	variable.

   Startup and shutdown
       A login shell begins  by	 executing  commands  from  the	 system	 files
       /etc/csh.cshrc  and  /etc/csh.login.   It  then	executes commands from
       files in	the user's home	directory: first ~/.tcshrc (+) or,  if	~/.tc-
       shrc is not found, ~/.cshrc, then ~/.history (or	the value of the hist-
       file shell variable), then ~/.login, and	 finally  ~/.cshdirs  (or  the
       value  of  the  dirsfile	 shell	variable)  (+).	  The  shell  may read
       /etc/csh.login before instead of	after /etc/csh.cshrc, and ~/.login be-
       fore  instead of	after ~/.tcshrc	or ~/.cshrc and	~/.history, if so com-
       piled; see the version shell variable. (+)

       Non-login shells	read only /etc/csh.cshrc and ~/.tcshrc or ~/.cshrc  on
       startup.

       For  examples  of  startup  files, please consult http://tcshrc.source-
       forge.net.

       Commands	like stty(1) and tset(1), which	need be	run only once per  lo-
       gin, usually go in one's	~/.login file.	Users who need to use the same
       set of files with both csh(1) and tcsh can have only a  ~/.cshrc	 which
       checks for the existence	of the tcsh shell variable (q.v.) before using
       tcsh-specific commands, or can have both	a  ~/.cshrc  and  a  ~/.tcshrc
       which  sources  (see  the  builtin command) ~/.cshrc.  The rest of this
       manual uses `~/.tcshrc' to mean `~/.tcshrc  or,	if  ~/.tcshrc  is  not
       found, ~/.cshrc'.

       In  the	normal case, the shell begins reading commands from the	termi-
       nal, prompting with `> '.  (Processing of arguments and the use of  the
       shell to	process	files containing command scripts are described later.)
       The shell repeatedly reads a line of  command  input,  breaks  it  into
       words,  places  it  on the command history list,	parses it and executes
       each command in the line.

       One can log out by typing `^D' on an empty line,	`logout' or `login' or
       via  the	 shell's  autologout mechanism (see the	autologout shell vari-
       able).  When a login shell terminates it	sets the logout	shell variable
       to  `normal' or `automatic' as appropriate, then	executes commands from
       the files /etc/csh.logout and ~/.logout.	 The shell may drop DTR	on lo-
       gout if so compiled; see	the version shell variable.

       The names of the	system login and logout	files vary from	system to sys-
       tem for compatibility with different csh(1) variants; see FILES.

   Editing
       We first	describe The command-line editor.  The Completion and  listing
       and  Spelling  correction  sections  describe two sets of functionality
       that are	implemented as editor commands but  which  deserve  their  own
       treatment.   Finally,  Editor  commands	lists and describes the	editor
       commands	specific to the	shell and their	default	bindings.

   The command-line editor (+)
       Command-line input can be edited	using key sequences  much  like	 those
       used  in	 GNU  Emacs or vi(1).  The editor is active only when the edit
       shell variable is set, which it is by default  in  interactive  shells.
       The  bindkey  builtin can display and change key	bindings.  Emacs-style
       key bindings are	used by	default	(unless	the shell was compiled	other-
       wise;  see  the version shell variable),	but bindkey can	change the key
       bindings	to vi-style bindings en	masse.

       The shell always	binds the arrow	keys (as defined in the	TERMCAP	 envi-
       ronment variable) to

	   down	   down-history
	   up	   up-history
	   left	   backward-char
	   right   forward-char

       unless  doing so	would alter another single-character binding.  One can
       set the arrow key escape	sequences to the empty string  with  settc  to
       prevent	these  bindings.   The ANSI/VT100 sequences for	arrow keys are
       always bound.

       Other key bindings are, for the most part, what Emacs and  vi(1)	 users
       would  expect  and  can	easily be displayed by bindkey,	so there is no
       need to list them here.	Likewise, bindkey can list the editor commands
       with a short description	of each.

       Note  that editor commands do not have the same notion of a ``word'' as
       does the	shell.	The editor delimits words  with	 any  non-alphanumeric
       characters  not in the shell variable wordchars,	while the shell	recog-
       nizes only whitespace and some of the characters	with special  meanings
       to it, listed under Lexical structure.

   Completion and listing (+)
       The shell is often able to complete words when given a unique abbrevia-
       tion.  Type part	of a word (for example `ls /usr/lost') and hit the tab
       key  to	run the	complete-word editor command.  The shell completes the
       filename	`/usr/lost' to `/usr/lost+found/',  replacing  the  incomplete
       word  with  the	complete word in the input buffer.  (Note the terminal
       `/'; completion adds a `/' to the end of	completed  directories	and  a
       space  to the end of other completed words, to speed typing and provide
       a visual	indicator of successful	completion.  The addsuffix shell vari-
       able  can  be  unset  to	 prevent this.)	 If no match is	found (perhaps
       `/usr/lost+found' doesn't exist), the terminal bell rings.  If the word
       is  already complete (perhaps there is a	`/usr/lost' on your system, or
       perhaps you were	thinking too far ahead and typed the  whole  thing)  a
       `/' or space is added to	the end	if it isn't already there.

       Completion  works  anywhere in the line,	not at just the	end; completed
       text pushes the rest of the line	to the right.  Completion in the  mid-
       dle  of a word often results in leftover	characters to the right	of the
       cursor that need	to be deleted.

       Commands	and variables can be completed in much the same	way.  For  ex-
       ample,  typing  `em[tab]'  would	complete `em' to `emacs' if emacs were
       the only	command	on your	system beginning with  `em'.   Completion  can
       find  a	command	 in any	directory in path or if	given a	full pathname.
       Typing `echo $ar[tab]' would complete `$ar'  to	`$argv'	 if  no	 other
       variable	began with `ar'.

       The  shell  parses  the	input buffer to	determine whether the word you
       want to complete	should be completed as a filename,  command  or	 vari-
       able.   The  first word in the buffer and the first word	following `;',
       `|', `|&', `&&' or `||' is considered to	be a command.  A  word	begin-
       ning with `$' is	considered to be a variable.  Anything else is a file-
       name.  An empty line is `completed' as a	filename.

       You can list the	possible completions of	a word at any time  by	typing
       `^D'  to	 run the delete-char-or-list-or-eof editor command.  The shell
       lists the possible completions using the	ls-F builtin (q.v.)   and  re-
       prints the prompt and unfinished	command	line, for example:

	   > ls	/usr/l[^D]
	   lbin/       lib/	   local/      lost+found/
	   > ls	/usr/l

       If  the	autolist  shell	variable is set, the shell lists the remaining
       choices (if any)	whenever completion fails:

	   > set autolist
	   > nm	/usr/lib/libt[tab]
	   libtermcap.a@ libtermlib.a@
	   > nm	/usr/lib/libterm

       If autolist is set to `ambiguous', choices are listed only when comple-
       tion fails and adds no new characters to	the word being completed.

       A  filename  to be completed can	contain	variables, your	own or others'
       home directories	abbreviated with `~' (see Filename  substitution)  and
       directory  stack	entries	abbreviated with `=' (see Directory stack sub-
       stitution).  For	example,

	   > ls	~k[^D]
	   kahn	   kas	   kellogg
	   > ls	~ke[tab]
	   > ls	~kellogg/

       or

	   > set local = /usr/local
	   > ls	$lo[tab]
	   > ls	$local/[^D]
	   bin/	etc/ lib/ man/ src/
	   > ls	$local/

       Note that variables can also be expanded	explicitly  with  the  expand-
       variables editor	command.

       delete-char-or-list-or-eof  lists  at  only the end of the line;	in the
       middle of a line	it deletes the character under the cursor  and	on  an
       empty  line  it	logs  one  out	or, if ignoreeof is set, does nothing.
       `M-^D', bound to	the editor command list-choices, lists completion pos-
       sibilities  anywhere on a line, and list-choices	(or any	one of the re-
       lated editor commands that do or	don't delete,  list  and/or  log  out,
       listed  under delete-char-or-list-or-eof) can be	bound to `^D' with the
       bindkey builtin command if so desired.

       The complete-word-fwd and complete-word-back editor commands (not bound
       to  any	keys  by default) can be used to cycle up and down through the
       list of possible	completions, replacing the current word	with the  next
       or previous word	in the list.

       The  shell  variable fignore can	be set to a list of suffixes to	be ig-
       nored by	completion.  Consider the following:

	   > ls
	   Makefile	   condiments.h~   main.o	   side.c
	   README	   main.c	   meal		   side.o
	   condiments.h	   main.c~
	   > set fignore = (.o \~)
	   > emacs ma[^D]
	   main.c   main.c~  main.o
	   > emacs ma[tab]
	   > emacs main.c

       `main.c~' and `main.o' are ignored by completion	(but not listing), be-
       cause  they  end	in suffixes in fignore.	 Note that a `\' was needed in
       front of	`~' to prevent it from being expanded to home as described un-
       der  Filename  substitution.  fignore is	ignored	if only	one completion
       is possible.

       If the complete shell variable is set to	`enhance', completion  1)  ig-
       nores  case and 2) considers periods, hyphens and underscores (`.', `-'
       and `_')	to be word separators and hyphens and underscores to be	equiv-
       alent.  If you had the following	files

	   comp.lang.c	    comp.lang.perl   comp.std.c++
	   comp.lang.c++    comp.std.c

       and  typed  `mail  -f  c.l.c[tab]',  it	would be completed to `mail -f
       comp.lang.c', and ^D  would  list  `comp.lang.c'	 and  `comp.lang.c++'.
       `mail  -f  c..c++[^D]'  would  list `comp.lang.c++' and `comp.std.c++'.
       Typing `rm a--file[^D]' in the following	directory

	   A_silly_file	   a-hyphenated-file	another_silly_file

       would list all three files, because case	is ignored and hyphens and un-
       derscores  are equivalent.  Periods, however, are not equivalent	to hy-
       phens or	underscores.

       Completion and listing are affected by several other  shell  variables:
       recexact	 can be	set to complete	on the shortest	possible unique	match,
       even if more typing might result	in a longer match:

	   > ls
	   fodder   foo	     food     foonly
	   > set recexact
	   > rm	fo[tab]

       just beeps, because `fo'	could expand to	`fod' or `foo',	but if we type
       another `o',

	   > rm	foo[tab]
	   > rm	foo

       the completion completes	on `foo', even though `food' and `foonly' also
       match.  autoexpand can be set to	run the	expand-history editor  command
       before each completion attempt, autocorrect can be set to spelling-cor-
       rect the	word to	be completed (see  Spelling  correction)  before  each
       completion attempt and correct can be set to complete commands automat-
       ically after one	hits `return'.	matchbeep can be set to	 make  comple-
       tion beep or not	beep in	a variety of situations, and nobeep can	be set
       to never	beep at	all.  nostat can be  set  to  a	 list  of  directories
       and/or patterns that match directories to prevent the completion	mecha-
       nism from stat(2)ing those directories.	listmax	and listmaxrows	can be
       set  to	limit  the  number  of	items and rows (respectively) that are
       listed without asking first.  recognize_only_executables	can be set  to
       make  the  shell	list only executables when listing commands, but it is
       quite slow.

       Finally,	the complete builtin command can be used to tell the shell how
       to  complete  words other than filenames, commands and variables.  Com-
       pletion and listing do not work on glob-patterns	(see Filename  substi-
       tution),	 but  the  list-glob  and  expand-glob editor commands perform
       equivalent functions for	glob-patterns.

   Spelling correction (+)
       The shell can sometimes correct the spelling of filenames, commands and
       variable	names as well as completing and	listing	them.

       Individual  words  can be spelling-corrected with the spell-word	editor
       command (usually	bound to M-s and M-S) and the entire input buffer with
       spell-line  (usually  bound to M-$).  The correct shell variable	can be
       set to `cmd' to correct the command name	or `all' to correct the	entire
       line  each  time	return is typed, and autocorrect can be	set to correct
       the word	to be completed	before each completion attempt.

       When spelling correction	is invoked in any of these ways	and the	 shell
       thinks that any part of the command line	is misspelled, it prompts with
       the corrected line:

	   > set correct = cmd
	   > lz	/usr/bin
	   CORRECT>ls /usr/bin (y|n|e|a)?

       One can answer `y' or space to execute the corrected line, `e' to leave
       the  uncorrected	 command in the	input buffer, `a' to abort the command
       as if `^C' had been hit,	and anything else to execute the original line
       unchanged.

       Spelling	 correction  recognizes	user-defined completions (see the com-
       plete builtin command).	If an input word in a  position	 for  which  a
       completion is defined resembles a word in the completion	list, spelling
       correction registers a misspelling and suggests the latter  word	 as  a
       correction.   However, if the input word	does not match any of the pos-
       sible completions for that position, spelling correction	does not  reg-
       ister a misspelling.

       Like  completion, spelling correction works anywhere in the line, push-
       ing the rest of the line	to the right and possibly leaving extra	 char-
       acters to the right of the cursor.

       Beware:	spelling  correction is	not guaranteed to work the way one in-
       tends, and is provided mostly as	an experimental	feature.   Suggestions
       and improvements	are welcome.

   Editor commands (+)
       `bindkey'  lists	 key  bindings	and `bindkey -l' lists and briefly de-
       scribes editor commands.	 Only new  or  especially  interesting	editor
       commands	 are  described	here.  See emacs(1) and	vi(1) for descriptions
       of each editor's	key bindings.

       The character or	characters to which each command is bound  by  default
       is  given  in  parentheses.  `^character' means a control character and
       `M-character' a meta character, typed as	escape-character on  terminals
       without	a  meta	key.  Case counts, but commands	that are bound to let-
       ters by default are bound to both lower-	and uppercase letters for con-
       venience.

       complete-word (tab)
	       Completes a word	as described under Completion and listing.

       complete-word-back (not bound)
	       Like complete-word-fwd, but steps up from the end of the	list.

       complete-word-fwd (not bound)
	       Replaces	 the  current  word with the first word	in the list of
	       possible	completions.  May be repeated to step down through the
	       list.   At the end of the list, beeps and reverts to the	incom-
	       plete word.

       complete-word-raw (^X-tab)
	       Like complete-word, but ignores user-defined completions.

       copy-prev-word (M-^_)
	       Copies the previous word	in the current	line  into  the	 input
	       buffer.	See also insert-last-word.

       dabbrev-expand (M-/)
	       Expands	the  current word to the most recent preceding one for
	       which the current is a leading substring, wrapping  around  the
	       history	list  (once)  if  necessary.  Repeating	dabbrev-expand
	       without any intervening typing changes  to  the	next  previous
	       word etc., skipping identical matches much like history-search-
	       backward	does.

       delete-char (not	bound)
	       Deletes the character under the cursor.	See also  delete-char-
	       or-list-or-eof.

       delete-char-or-eof (not bound)
	       Does  delete-char  if  there is a character under the cursor or
	       end-of-file on an empty line.  See also delete-char-or-list-or-
	       eof.

       delete-char-or-list (not	bound)
	       Does  delete-char  if  there is a character under the cursor or
	       list-choices at the end of the line.  See also  delete-char-or-
	       list-or-eof.

       delete-char-or-list-or-eof (^D)
	       Does  delete-char  if  there  is	 a character under the cursor,
	       list-choices at the end of the line or end-of-file on an	 empty
	       line.  See also those three commands, each of which does	only a
	       single action, and delete-char-or-eof, delete-char-or-list  and
	       list-or-eof,  each  of  which  does  a different	two out	of the
	       three.

       down-history (down-arrow, ^N)
	       Like up-history,	but steps down,	stopping at the	original input
	       line.

       end-of-file (not	bound)
	       Signals	an  end	 of file, causing the shell to exit unless the
	       ignoreeof shell variable	(q.v.) is set to  prevent  this.   See
	       also delete-char-or-list-or-eof.

       expand-history (M-space)
	       Expands history substitutions in	the current word.  See History
	       substitution.  See also magic-space, toggle-literal-history and
	       the autoexpand shell variable.

       expand-glob (^X-*)
	       Expands	the glob-pattern to the	left of	the cursor.  See File-
	       name substitution.

       expand-line (not	bound)
	       Like expand-history, but	expands	history	substitutions in  each
	       word in the input buffer,

       expand-variables	(^X-$)
	       Expands	the  variable to the left of the cursor.  See Variable
	       substitution.

       history-search-backward (M-p, M-P)
	       Searches	backwards through the history list for a  command  be-
	       ginning with the	current	contents of the	input buffer up	to the
	       cursor and copies it into the input buffer.  The	search	string
	       may  be	a  glob-pattern	(see Filename substitution) containing
	       `*', `?', `[]' or `{}'.	up-history and down-history will  pro-
	       ceed  from  the	appropriate  point in the history list.	 Emacs
	       mode only.  See also history-search-forward and i-search-back.

       history-search-forward (M-n, M-N)
	       Like history-search-backward, but searches forward.

       i-search-back (not bound)
	       Searches	 backward  like	 history-search-backward,  copies  the
	       first match into	the input buffer with the cursor positioned at
	       the end of the pattern, and prompts with	`bck: '	and the	 first
	       match.	Additional  characters	may  be	 typed	to  extend the
	       search, i-search-back may be typed to continue  searching  with
	       the  same  pattern,  wrapping around the	history	list if	neces-
	       sary, (i-search-back must be bound to a	single	character  for
	       this to work) or	one of the following special characters	may be
	       typed:

		   ^W	   Appends the rest of the word	under  the  cursor  to
			   the search pattern.
		   delete (or any character bound to backward-delete-char)
			   Undoes  the	effect of the last character typed and
			   deletes a character from the	search pattern if  ap-
			   propriate.
		   ^G	   If  the  previous search was	successful, aborts the
			   entire search.  If not, goes	back to	the last  suc-
			   cessful search.
		   escape  Ends	 the  search,  leaving the current line	in the
			   input buffer.

	       Any other character not bound to	self-insert-command terminates
	       the  search,  leaving the current line in the input buffer, and
	       is then interpreted as normal input.  In	particular, a carriage
	       return  causes  the  current  line  to be executed.  Emacs mode
	       only.  See also i-search-fwd and	history-search-backward.

       i-search-fwd (not bound)
	       Like i-search-back, but searches	forward.

       insert-last-word	(M-_)
	       Inserts the last	word of	the previous input  line  (`!$')  into
	       the input buffer.  See also copy-prev-word.

       list-choices (M-^D)
	       Lists  completion  possibilities	 as described under Completion
	       and listing.  See  also	delete-char-or-list-or-eof  and	 list-
	       choices-raw.

       list-choices-raw	(^X-^D)
	       Like list-choices, but ignores user-defined completions.

       list-glob (^X-g,	^X-G)
	       Lists  (via  the	ls-F builtin) matches to the glob-pattern (see
	       Filename	substitution) to the left of the cursor.

       list-or-eof (not	bound)
	       Does list-choices or end-of-file	on an empty  line.   See  also
	       delete-char-or-list-or-eof.

       magic-space (not	bound)
	       Expands history substitutions in	the current line, like expand-
	       history,	and inserts a space.  magic-space is  designed	to  be
	       bound to	the space bar, but is not bound	by default.

       normalize-command (^X-?)
	       Searches	 for the current word in PATH and, if it is found, re-
	       places it with the full path to the executable.	Special	 char-
	       acters  are  quoted.   Aliases are expanded and quoted but com-
	       mands within aliases are	not.  This command is useful with com-
	       mands that take commands	as arguments, e.g., `dbx' and `sh -x'.

       normalize-path (^X-n, ^X-N)
	       Expands	the  current word as described under the `expand' set-
	       ting of the symlinks shell variable.

       overwrite-mode (unbound)
	       Toggles between input and overwrite modes.

       run-fg-editor (M-^Z)
	       Saves the current input line and	looks for a stopped job	with a
	       name  equal  to the last	component of the file name part	of the
	       EDITOR or VISUAL	environment variables, or, if neither is  set,
	       `ed'  or	 `vi'.	 If such a job is found, it is restarted as if
	       `fg %job' had been typed.  This is  used	 to  toggle  back  and
	       forth between an	editor and the shell easily.  Some people bind
	       this command to `^Z' so they can	do this	even more easily.

       run-help	(M-h, M-H)
	       Searches	for documentation on the current  command,  using  the
	       same  notion  of	 `current command' as the completion routines,
	       and prints it.  There is	no way to use a	pager; run-help	is de-
	       signed  for short help files.  If the special alias helpcommand
	       is defined, it is run with the command name as a	sole argument.
	       Else,  documentation  should  be	 in a file named command.help,
	       command.1, command.6, command.8 or command, which should	be  in
	       one  of	the  directories listed	in the HPATH environment vari-
	       able.  If there is more than one	help file only	the  first  is
	       printed.

       self-insert-command (text characters)
	       In  insert mode (the default), inserts the typed	character into
	       the input line after the	character under	the cursor.  In	 over-
	       write  mode,  replaces  the character under the cursor with the
	       typed character.	 The input mode	is normally preserved  between
	       lines,  but the inputmode shell variable	can be set to `insert'
	       or `overwrite' to put the editor	in that	mode at	the  beginning
	       of each line.  See also overwrite-mode.

       sequence-lead-in	(arrow prefix, meta prefix, ^X)
	       Indicates that the following characters are part	of a multi-key
	       sequence.  Binding a command to	a  multi-key  sequence	really
	       creates	two  bindings: the first character to sequence-lead-in
	       and the whole sequence to the command.  All sequences beginning
	       with  a	character  bound  to  sequence-lead-in are effectively
	       bound to	undefined-key unless bound to another command.

       spell-line (M-$)
	       Attempts	to correct the spelling	of each	word in	the input buf-
	       fer,  like  spell-word, but ignores words whose first character
	       is one of `-', `!', `^' or `%', or which	contain	 `\',  `*'  or
	       `?',  to	 avoid	problems  with switches, substitutions and the
	       like.  See Spelling correction.

       spell-word (M-s,	M-S)
	       Attempts	to correct the spelling	of the	current	 word  as  de-
	       scribed	under Spelling correction.  Checks each	component of a
	       word which appears to be	a pathname.

       toggle-literal-history (M-r, M-R)
	       Expands or `unexpands' history substitutions in the input  buf-
	       fer.   See  also	 expand-history	and the	autoexpand shell vari-
	       able.

       undefined-key (any unbound key)
	       Beeps.

       up-history (up-arrow, ^P)
	       Copies the previous entry in the	history	list  into  the	 input
	       buffer.	If histlit is set, uses	the literal form of the	entry.
	       May be repeated to step up through the history  list,  stopping
	       at the top.

       vi-search-back (?)
	       Prompts	with `?' for a search string (which may	be a glob-pat-
	       tern, as	with history-search-backward),	searches  for  it  and
	       copies it into the input	buffer.	 The bell rings	if no match is
	       found.  Hitting return ends the	search	and  leaves  the  last
	       match  in the input buffer.  Hitting escape ends	the search and
	       executes	the match.  vi mode only.

       vi-search-fwd (/)
	       Like vi-search-back, but	searches forward.

       which-command (M-?)
	       Does a which (see the description of the	 builtin  command)  on
	       the first word of the input buffer.

       yank-pop	(M-y)
	       When executed immediately after a yank or another yank-pop, re-
	       places the yanked string	with the next previous string from the
	       killring.  This	also  has the effect of	rotating the killring,
	       such that this string will  be  considered  the	most  recently
	       killed  by  a later yank	command. Repeating yank-pop will cycle
	       through the killring any	number of times.

   Lexical structure
       The shell splits	input lines into words at blanks and tabs.   The  spe-
       cial  characters	 `&', `|', `;',	`<', `>', `(', and `)' and the doubled
       characters `&&',	`||', `<<' and `>>' are	always separate	words, whether
       or not they are surrounded by whitespace.

       When the	shell's	input is not a terminal, the character `#' is taken to
       begin a comment.	 Each `#' and the rest of the input line on  which  it
       appears is discarded before further parsing.

       A  special  character  (including a blank or tab) may be	prevented from
       having its special meaning, and possibly	made part of another word,  by
       preceding  it  with  a backslash	(`\') or enclosing it in single	(`''),
       double (`"') or backward	(``') quotes.  When  not  otherwise  quoted  a
       newline	preceded  by a `\' is equivalent to a blank, but inside	quotes
       this sequence results in	a newline.

       Furthermore, all	Substitutions (see below) except History  substitution
       can  be	prevented  by  enclosing  the strings (or parts	of strings) in
       which they appear with single quotes or by quoting the crucial  charac-
       ter(s) (e.g., `$' or ``'	for Variable substitution or Command substitu-
       tion respectively) with `\'.   (Alias  substitution  is	no  exception:
       quoting	in any way any character of a word for which an	alias has been
       defined prevents	substitution of	the alias.  The	usual way  of  quoting
       an  alias  is  to precede it with a backslash.) History substitution is
       prevented by backslashes	but not	by single quotes.  Strings quoted with
       double  or  backward  quotes  undergo Variable substitution and Command
       substitution, but other substitutions are prevented.

       Text inside single or double quotes becomes a single word (or  part  of
       one).   Metacharacters  in these	strings, including blanks and tabs, do
       not form	separate words.	 Only in one special case (see Command substi-
       tution  below)  can a double-quoted string yield	parts of more than one
       word; single-quoted strings never do.   Backward	 quotes	 are  special:
       they  signal Command substitution (q.v.), which may result in more than
       one word.

       Quoting complex strings,	particularly strings which themselves  contain
       quoting characters, can be confusing.  Remember that quotes need	not be
       used as they are	in human writing!  It may be easier to	quote  not  an
       entire  string,	but only those parts of	the string which need quoting,
       using different types of	quoting	to do so if appropriate.

       The backslash_quote shell variable (q.v.) can  be  set  to  make	 back-
       slashes	always	quote  `\',  `'',  and `"'.  (+) This may make complex
       quoting tasks easier, but it can	cause syntax errors in csh(1) scripts.

   Substitutions
       We now describe the various transformations the shell performs  on  the
       input  in  the  order in	which they occur.  We note in passing the data
       structures involved and the commands and	variables which	 affect	 them.
       Remember	 that  substitutions  can be prevented by quoting as described
       under Lexical structure.

   History substitution
       Each command, or	``event'', input from the terminal  is	saved  in  the
       history	list.	The  previous command is always	saved, and the history
       shell variable can be set to a number to	save that many commands.   The
       histdup	shell variable can be set to not save duplicate	events or con-
       secutive	duplicate events.

       Saved commands are numbered sequentially	from 1 and  stamped  with  the
       time.   It  is not usually necessary to use event numbers, but the cur-
       rent event number can be	made part of the prompt	by placing an  `!'  in
       the prompt shell	variable.

       The  shell  actually saves history in expanded and literal (unexpanded)
       forms.  If the histlit shell variable is	set, commands that display and
       store history use the literal form.

       The  history  builtin  command  can print, store	in a file, restore and
       clear the history list at any time, and the savehist and	histfile shell
       variables  can be can be	set to store the history list automatically on
       logout and restore it on	login.

       History substitutions introduce words from the history  list  into  the
       input  stream, making it	easy to	repeat commands, repeat	arguments of a
       previous	command	in the current command,	or fix	spelling  mistakes  in
       the  previous  command  with  little typing and a high degree of	confi-
       dence.

       History substitutions begin with	the character  `!'.   They  may	 begin
       anywhere	 in  the  input	 stream, but they do not nest.	The `!'	may be
       preceded	by a `\' to prevent its	special	meaning;  for  convenience,  a
       `!'  is	passed unchanged when it is followed by	a blank, tab, newline,
       `=' or `('.  History substitutions also occur when an input line	begins
       with  `^'.   This  special  abbreviation	 will be described later.  The
       characters used to signal history substitution (`!'  and	 `^')  can  be
       changed	by setting the histchars shell variable.  Any input line which
       contains	a history substitution is printed before it is executed.

       A history substitution may have an ``event specification'', which indi-
       cates  the  event  from	which words are	to be taken, a ``word designa-
       tor'', which selects particular words from the chosen event,  and/or  a
       ``modifier'', which manipulates the selected words.

       An event	specification can be

	   n	   A number, referring to a particular event
	   -n	   An  offset,	referring  to  the  event n before the current
		   event
	   #	   The current	event.	 This  should  be  used	 carefully  in
		   csh(1), where there is no check for recursion.  tcsh	allows
		   10 levels of	recursion.  (+)
	   !	   The previous	event (equivalent to `-1')
	   s	   The most recent event whose	first  word  begins  with  the
		   string s
	   ?s?	   The	most  recent  event  which contains the	string s.  The
		   second `?' can be omitted if	it is immediately followed  by
		   a newline.

       For example, consider this bit of someone's history list:

	    9  8:30    nroff -man wumpus.man
	   10  8:31    cp wumpus.man wumpus.man.old
	   11  8:36    vi wumpus.man
	   12  8:37    diff wumpus.man.old wumpus.man

       The  commands  are shown	with their event numbers and time stamps.  The
       current event, which we haven't typed in	yet, is	event 13.   `!11'  and
       `!-2'  refer to event 11.  `!!' refers to the previous event, 12.  `!!'
       can be abbreviated `!' if it is followed	by `:' (`:' is	described  be-
       low).   `!n'  refers  to	event 9, which begins with `n'.	 `!?old?' also
       refers to event 12, which contains `old'.  Without word designators  or
       modifiers  history  references simply expand to the entire event, so we
       might type `!cp'	to redo	the copy command or `!!|more'  if  the	`diff'
       output scrolled off the top of the screen.

       History	references  may	 be  insulated	from the surrounding text with
       braces if necessary.  For example, `!vdoc' would	look for a command be-
       ginning	with `vdoc', and, in this example, not find one, but `!{v}doc'
       would expand unambiguously to `vi wumpus.mandoc'.  Even in braces, his-
       tory substitutions do not nest.

       (+) While csh(1)	expands, for example, `!3d' to event 3 with the	letter
       `d' appended to it, tcsh	expands	it to the last	event  beginning  with
       `3d';  only  completely numeric arguments are treated as	event numbers.
       This makes it possible to recall	events beginning with numbers.	To ex-
       pand `!3d' as in	csh(1) say `!{3}d'.

       To  select words	from an	event we can follow the	event specification by
       a `:' and a designator for the desired words.  The words	 of  an	 input
       line are	numbered from 0, the first (usually command) word being	0, the
       second word (first argument) being 1, etc.  The basic word  designators
       are:

	   0	   The first (command) word
	   n	   The nth argument
	   ^	   The first argument, equivalent to `1'
	   $	   The last argument
	   %	   The word matched by an ?s? search
	   x-y	   A range of words
	   -y	   Equivalent to `0-y'
	   *	   Equivalent  to `^-$', but returns nothing if	the event con-
		   tains only 1	word
	   x*	   Equivalent to `x-$'
	   x-	   Equivalent to `x*', but omitting the	last word (`$')

       Selected	words are inserted into	the command line separated  by	single
       blanks.	 For example, the `diff' command in the	previous example might
       have been typed as `diff	!!:1.old !!:1' (using `:1' to select the first
       argument	 from  the previous event) or `diff !-2:2 !-2:1' to select and
       swap the	arguments from the `cp'	command.  If we	didn't care about  the
       order  of  the `diff' we	might have said	`diff !-2:1-2' or simply `diff
       !-2:*'.	The `cp'  command  might  have	been  written  `cp  wumpus.man
       !#:1.old',  using `#' to	refer to the current event.  `!n:- hurkle.man'
       would reuse the first two words from the	`nroff'	command	to say	`nroff
       -man hurkle.man'.

       The `:' separating the event specification from the word	designator can
       be omitted if the argument selector begins with a `^', `$', `*',	`%' or
       `-'.   For  example,  our  `diff' command might have been `diff !!^.old
       !!^' or,	equivalently, `diff !!$.old !!$'.  However, if `!!' is	abbre-
       viated `!', an argument selector	beginning with `-' will	be interpreted
       as an event specification.

       A history reference may have a word designator but no event  specifica-
       tion.   It then references the previous command.	 Continuing our	`diff'
       example,	we could have said simply `diff	!^.old !^' or, to get the  ar-
       guments in the opposite order, just `diff !*'.

       The  word  or  words  in	 a history reference can be edited, or ``modi-
       fied'', by following it with one	or more	modifiers, each	preceded by  a
       `:':

	   h	   Remove a trailing pathname component, leaving the head.
	   t	   Remove all leading pathname components, leaving the tail.
	   r	   Remove a filename extension `.xxx', leaving the root	name.
	   e	   Remove all but the extension.
	   u	   Uppercase the first lowercase letter.
	   l	   Lowercase the first uppercase letter.
	   s/l/r/  Substitute  l  for  r.   l is simply	a string like r, not a
		   regular expression as in the	eponymous ed(1)	command.   Any
		   character  may  be used as the delimiter in place of	`/'; a
		   `\' can be used to quote the	delimiter inside l and r.  The
		   character  `&'  in  the r is	replaced by l; `\' also	quotes
		   `&'.	 If l is empty (``''), the l from a previous substitu-
		   tion	 or  the  s  from a previous search or event number in
		   event specification is used.	 The trailing delimiter	may be
		   omitted if it is immediately	followed by a newline.
	   &	   Repeat the previous substitution.
	   g	   Apply the following modifier	once to	each word.
	   a (+)   Apply the following modifier	as many	times as possible to a
		   single word.	 `a' and `g' can be used together to  apply  a
		   modifier  globally.	 With  the `s' modifier, only the pat-
		   terns contained in the original word	are  substituted,  not
		   patterns that contain any substitution result.
	   p	   Print the new command line but do not execute it.
	   q	   Quote  the  substituted words, preventing further substitu-
		   tions.
	   x	   Like	q, but break into words	at blanks, tabs	and newlines.

       Modifiers are applied to	only the first modifiable word (unless `g'  is
       used).  It is an	error for no word to be	modifiable.

       For  example,  the `diff' command might have been written as `diff wum-
       pus.man.old !#^:r', using `:r' to remove	`.old' from the	first argument
       on  the	same  line (`!#^').  We	could say `echo	hello out there', then
       `echo !*:u' to capitalize `hello', `echo	!*:au' to say it out loud,  or
       `echo  !*:agu'  to really shout.	 We might follow `mail -s "I forgot my
       password" rot' with `!:s/rot/root' to correct the  spelling  of	`root'
       (but see	Spelling correction for	a different approach).

       There is	a special abbreviation for substitutions.  `^',	when it	is the
       first character on an input line, is equivalent	to  `!:s^'.   Thus  we
       might have said `^rot^root' to make the spelling	correction in the pre-
       vious example.  This is the only	history	substitution  which  does  not
       explicitly begin	with `!'.

       (+) In csh as such, only	one modifier may be applied to each history or
       variable	expansion.  In tcsh, more than one may be used,	for example

	   % mv	wumpus.man /usr/man/man1/wumpus.1
	   % man !$:t:r
	   man wumpus

       In csh, the result would	be `wumpus.1:r'.  A substitution followed by a
       colon may need to be insulated from it with braces:

	   > mv	a.out /usr/games/wumpus
	   > setenv PATH !$:h:$PATH
	   Bad ! modifier: $.
	   > setenv PATH !{-2$:h}:$PATH
	   setenv PATH /usr/games:/bin:/usr/bin:.

       The  first attempt would	succeed	in csh but fails in tcsh, because tcsh
       expects another modifier	after the second colon rather than `$'.

       Finally,	history	can be accessed	through	the editor as well as  through
       the  substitutions  just	described.  The	up- and	down-history, history-
       search-backward and -forward, i-search-back  and	 -fwd,	vi-search-back
       and  -fwd,  copy-prev-word  and insert-last-word	editor commands	search
       for events in the history list and copy them  into  the	input  buffer.
       The toggle-literal-history editor command switches between the expanded
       and literal forms of history lines in the input buffer.	expand-history
       and expand-line expand history substitutions in the current word	and in
       the entire input	buffer respectively.

   Alias substitution
       The shell maintains a list of aliases  which  can  be  set,  unset  and
       printed	by  the	 alias	and unalias commands.  After a command line is
       parsed into simple commands (see	Commands) the first word of each  com-
       mand,  left-to-right, is	checked	to see if it has an alias.  If so, the
       first word is replaced by the alias.  If	the alias contains  a  history
       reference, it undergoes History substitution (q.v.) as though the orig-
       inal command were the previous input line.  If the alias	does not  con-
       tain a history reference, the argument list is left untouched.

       Thus if the alias for `ls' were `ls -l' the command `ls /usr' would be-
       come `ls	-l /usr', the argument list here being	undisturbed.   If  the
       alias  for `lookup' were	`grep !^ /etc/passwd' then `lookup bill' would
       become `grep bill /etc/passwd'.	 Aliases  can  be  used	 to  introduce
       parser metasyntax.  For example,	`alias print 'pr \!* | lpr'' defines a
       ``command'' (`print') which pr(1)s its arguments	to the line printer.

       Alias substitution is repeated until the	first word of the command  has
       no  alias.  If an alias substitution does not change the	first word (as
       in the previous example)	it is flagged to prevent a loop.  Other	 loops
       are detected and	cause an error.

       Some aliases are	referred to by the shell; see Special aliases.

   Variable substitution
       The  shell  maintains a list of variables, each of which	has as value a
       list of zero or more words.  The	values of shell	variables can be  dis-
       played  and  changed with the set and unset commands.  The system main-
       tains its own list of ``environment'' variables.	  These	 can  be  dis-
       played and changed with printenv, setenv	and unsetenv.

       (+)  Variables  may  be	made read-only with `set -r' (q.v.)  Read-only
       variables may not be modified or	unset; attempting to do	so will	 cause
       an  error.  Once	made read-only,	a variable cannot be made writable, so
       `set -r'	should be used with caution.  Environment variables cannot  be
       made read-only.

       Some  variables	are  set  by  the shell	or referred to by it.  For in-
       stance, the argv	variable is an image of	the shell's argument list, and
       words  of  this variable's value	are referred to	in special ways.  Some
       of the variables	referred to by the shell are toggles; the  shell  does
       not  care  what	their value is,	only whether they are set or not.  For
       instance, the verbose variable is a toggle which	causes	command	 input
       to  be echoed.  The -v command line option sets this variable.  Special
       shell variables lists all variables which are referred to by the	shell.

       Other operations	treat variables	numerically.  The `@' command  permits
       numeric calculations to be performed and	the result assigned to a vari-
       able.  Variable values are, however, always  represented	 as  (zero  or
       more) strings.  For the purposes	of numeric operations, the null	string
       is considered to	be zero, and the second	and subsequent words of	multi-
       word values are ignored.

       After  the input	line is	aliased	and parsed, and	before each command is
       executed, variable substitution is performed keyed by  `$'  characters.
       This  expansion can be prevented	by preceding the `$' with a `\'	except
       within `"'s where it always occurs, and within `''s where it never  oc-
       curs.  Strings quoted by	``' are	interpreted later (see Command substi-
       tution below) so	`$' substitution does not occur	there until later,  if
       at all.	A `$' is passed	unchanged if followed by a blank, tab, or end-
       of-line.

       Input/output redirections are recognized	before variable	expansion, and
       are  variable expanded separately.  Otherwise, the command name and en-
       tire argument list are expanded together.  It is	thus possible for  the
       first  (command)	 word  (to this	point) to generate more	than one word,
       the first of which becomes the command name, and	the rest of which  be-
       come arguments.

       Unless  enclosed	in `"' or given	the `:q' modifier the results of vari-
       able substitution may eventually	be command and	filename  substituted.
       Within  `"',  a variable	whose value consists of	multiple words expands
       to a (portion of	a) single word,	with the words of the variable's value
       separated  by blanks.  When the `:q' modifier is	applied	to a substitu-
       tion the	variable will expand to	multiple words with  each  word	 sepa-
       rated  by  a blank and quoted to	prevent	later command or filename sub-
       stitution.

       The following metasequences are provided	for introducing	variable  val-
       ues into	the shell input.  Except as noted, it is an error to reference
       a variable which	is not set.

       $name
       ${name} Substitutes the words of	the value of variable name, each sepa-
	       rated  by a blank.  Braces insulate name	from following charac-
	       ters which would	otherwise be part of it.  Shell	variables have
	       names  consisting of letters and	digits starting	with a letter.
	       The underscore character	is considered a	letter.	  If  name  is
	       not  a shell variable, but is set in the	environment, then that
	       value is	returned (but some of the other	forms given below  are
	       not available in	this case).
       $name[selector]
       ${name[selector]}
	       Substitutes  only  the  selected	 words from the	value of name.
	       The selector is subjected to `$'	substitution and  may  consist
	       of  a  single  number  or  two numbers separated	by a `-'.  The
	       first word of a variable's value	is numbered `1'.  If the first
	       number  of  a range is omitted it defaults to `1'.  If the last
	       member of a range is omitted it defaults	to `$#name'.  The  se-
	       lector  `*'  selects all	words.	It is not an error for a range
	       to be empty if the second argument is omitted or	in range.
       $0      Substitutes the name of the file	from which  command  input  is
	       being read.  An error occurs if the name	is not known.
       $number
       ${number}
	       Equivalent to `$argv[number]'.
       $*      Equivalent to `$argv', which is equivalent to `$argv[*]'.

       The  `:'	 modifiers  described  under  History substitution, except for
       `:p', can be applied to the substitutions above.	 More than one may  be
       used.   (+)  Braces  may	 be needed to insulate a variable substitution
       from a literal colon just as with History substitution (q.v.); any mod-
       ifiers must appear within the braces.

       The following substitutions can not be modified with `:'	modifiers.

       $?name
       ${?name}
	       Substitutes the string `1' if name is set, `0' if it is not.
       $?0     Substitutes  `1'	if the current input filename is known,	`0' if
	       it is not.  Always `0' in interactive shells.
       $#name
       ${#name}
	       Substitutes the number of words in name.
       $#      Equivalent to `$#argv'.	(+)
       $%name
       ${%name}
	       Substitutes the number of characters in name.  (+)
       $%number
       ${%number}
	       Substitutes the number of characters in $argv[number].  (+)
       $?      Equivalent to `$status'.	 (+)
       $$      Substitutes the (decimal) process number	of the (parent)	shell.
       $!      Substitutes the (decimal) process number	of the last background
	       process started by this shell.  (+)
       $_      Substitutes the command line of the last	command	executed.  (+)
       $<      Substitutes a line from the standard input, with	no further in-
	       terpretation thereafter.	 It can	be used	to read	from the  key-
	       board in	a shell	script.	 (+) While csh always quotes $<, as if
	       it were equivalent to `$<:q', tcsh does not.  Furthermore, when
	       tcsh is waiting for a line to be	typed the user may type	an in-
	       terrupt to interrupt the	sequence into which the	line is	to  be
	       substituted, but	csh does not allow this.

       The  editor  command expand-variables, normally bound to	`^X-$',	can be
       used to interactively expand individual variables.

   Command, filename and directory stack substitution
       The remaining substitutions are applied selectively to the arguments of
       builtin	commands.   This  means	that portions of expressions which are
       not evaluated are not subjected	to  these  expansions.	 For  commands
       which  are  not	internal to the	shell, the command name	is substituted
       separately from the argument list.  This	occurs very late, after	input-
       output redirection is performed,	and in a child of the main shell.

   Command substitution
       Command	substitution  is  indicated by a command enclosed in ``'.  The
       output from such	a command is broken into  separate  words  at  blanks,
       tabs  and  newlines, and	null words are discarded.  The output is vari-
       able and	command	substituted and	put in place of	the original string.

       Command substitutions inside double  quotes  (`"')  retain  blanks  and
       tabs; only newlines force new words.  The single	final newline does not
       force a new word	in any case.  It is thus possible for a	 command  sub-
       stitution  to  yield only part of a word, even if the command outputs a
       complete	line.

       By default, the shell since version 6.12	replaces all newline and  car-
       riage  return characters	in the command by spaces.  If this is switched
       off by unsetting	csubstnonl, newlines separate commands as usual.

   Filename substitution
       If a word contains any of the characters	`*', `?', `[' or `{' or	begins
       with  the  character  `~'  it is	a candidate for	filename substitution,
       also known as ``globbing''.  This word is then regarded	as  a  pattern
       (``glob-pattern''),  and	replaced with an alphabetically	sorted list of
       file names which	match the pattern.

       In matching filenames, the character `.'	at the beginning of a filename
       or  immediately	following  a `/', as well as the character `/' must be
       matched explicitly.  The	character `*' matches any  string  of  charac-
       ters,  including	the null string.  The character	`?' matches any	single
       character.  The sequence	`[...]'	matches	any one	of the characters  en-
       closed.	 Within	`[...]', a pair	of characters separated	by `-' matches
       any character lexically between the two.

       (+) Some	glob-patterns can be negated: The  sequence  `[^...]'  matches
       any  single  character not specified by the characters and/or ranges of
       characters in the braces.

       An entire glob-pattern can also be negated with `^':

	   > echo *
	   bang	crash crunch ouch
	   > echo ^cr*
	   bang	ouch

       Glob-patterns which do not use `?', `*',	or `[]'	or which use  `{}'  or
       `~' (below) are not negated correctly.

       The  metanotation  `a{b,c,d}e' is a shorthand for `abe ace ade'.	 Left-
       to-right	order is preserved: `/usr/source/s1/{oldls,ls}.c'  expands  to
       `/usr/source/s1/oldls.c	/usr/source/s1/ls.c'.	The results of matches
       are  sorted  separately	at  a  low  level  to  preserve	 this	order:
       `../{memo,*box}'	 might expand to `../memo ../box ../mbox'.  (Note that
       `memo' was not sorted with the results of matching `*box'.)  It is  not
       an  error  when this construct expands to files which do	not exist, but
       it is possible to get an	error from a command  to  which	 the  expanded
       list  is	 passed.  This construct may be	nested.	 As a special case the
       words `{', `}' and `{}' are passed undisturbed.

       The character `~' at the	beginning of a filename	refers to home	direc-
       tories.	 Standing  alone,  i.e., `~', it expands to the	invoker's home
       directory as reflected in the value of the home shell  variable.	  When
       followed	by a name consisting of	letters, digits	and `-'	characters the
       shell searches for a user with that name	and substitutes	their home di-
       rectory;	 thus  `~ken'  might expand to `/usr/ken' and `~ken/chmach' to
       `/usr/ken/chmach'.  If the character `~'	is  followed  by  a  character
       other  than  a letter or	`/' or appears elsewhere than at the beginning
       of a word, it is	left undisturbed.   A  command	like  `setenv  MANPATH
       /usr/man:/usr/local/man:~/lib/man'  does	not, therefore,	do home	direc-
       tory substitution as one	might hope.

       It is an	error for a glob-pattern containing `*', `?', `[' or `~', with
       or without `^', not to match any	files.	However, only one pattern in a
       list of glob-patterns must match	a file (so that,  e.g.,	 `rm  *.a  *.c
       *.o'  would  fail  only if there	were no	files in the current directory
       ending in `.a', `.c', or	`.o'), and if the nonomatch shell variable  is
       set  a  pattern (or list	of patterns) which matches nothing is left un-
       changed rather than causing an error.

       The noglob shell	variable can be	set to prevent filename	 substitution,
       and  the	 expand-glob  editor command, normally bound to	`^X-*',	can be
       used to interactively expand individual filename	substitutions.

   Directory stack substitution	(+)
       The directory stack is a	list of	directories, numbered from zero,  used
       by  the	pushd, popd and	dirs builtin commands (q.v.).  dirs can	print,
       store in	a file,	restore	and clear the directory	stack at any time, and
       the  savedirs  and dirsfile shell variables can be set to store the di-
       rectory stack automatically on logout and restore  it  on  login.   The
       dirstack	 shell variable	can be examined	to see the directory stack and
       set to put arbitrary directories	into the directory stack.

       The character `=' followed by one or more digits	expands	to an entry in
       the  directory stack.  The special case `=-' expands to the last	direc-
       tory in the stack.  For example,

	   > dirs -v
	   0	   /usr/bin
	   1	   /usr/spool/uucp
	   2	   /usr/accts/sys
	   > echo =1
	   /usr/spool/uucp
	   > echo =0/calendar
	   /usr/bin/calendar
	   > echo =-
	   /usr/accts/sys

       The noglob and nonomatch	shell variables	 and  the  expand-glob	editor
       command apply to	directory stack	as well	as filename substitutions.

   Other substitutions (+)
       There   are  several  more  transformations  involving  filenames,  not
       strictly	related	to the above but mentioned here	for completeness.  Any
       filename	 may  be  expanded  to	a full path when the symlinks variable
       (q.v.) is set to	`expand'.  Quoting prevents this  expansion,  and  the
       normalize-path editor command does it on	demand.	 The normalize-command
       editor command expands commands in PATH into full paths on demand.  Fi-
       nally, cd and pushd interpret `-' as the	old working directory (equiva-
       lent to the shell variable owd).	 This is not a	substitution  at  all,
       but an abbreviation recognized by only those commands.  Nonetheless, it
       too can be prevented by quoting.

   Commands
       The next	three sections describe	how the	shell  executes	 commands  and
       deals with their	input and output.

   Simple commands, pipelines and sequences
       A  simple  command is a sequence	of words, the first of which specifies
       the command to be executed.  A series of	simple commands	joined by  `|'
       characters  forms a pipeline.  The output of each command in a pipeline
       is connected to the input of the	next.

       Simple commands and pipelines may be joined into	 sequences  with  `;',
       and  will be executed sequentially.  Commands and pipelines can also be
       joined into sequences with `||' or `&&',	indicating, as in the  C  lan-
       guage,  that  the  second  is to	be executed only if the	first fails or
       succeeds	respectively.

       A simple	command, pipeline or sequence may be  placed  in  parentheses,
       `()',  to  form a simple	command, which may in turn be a	component of a
       pipeline	or sequence.  A	command, pipeline or sequence can be  executed
       without waiting for it to terminate by following	it with	an `&'.

   Builtin and non-builtin command execution
       Builtin	commands are executed within the shell.	 If any	component of a
       pipeline	except the last	is a builtin command, the pipeline is executed
       in a subshell.

       Parenthesized commands are always executed in a subshell.

	   (cd;	pwd); pwd

       thus  prints  the  home directory, leaving you where you	were (printing
       this after the home directory), while

	   cd; pwd

       leaves you in the home directory.  Parenthesized	commands are most  of-
       ten used	to prevent cd from affecting the current shell.

       When  a command to be executed is found not to be a builtin command the
       shell attempts to execute the command via execve(2).  Each word in  the
       variable	 path  names  a	directory in which the shell will look for the
       command.	 If the	shell is not given a -f	option,	the shell  hashes  the
       names  in  these	directories into an internal table so that it will try
       an execve(2) in only a directory	where there is a possibility that  the
       command	resides	 there.	  This	greatly	speeds command location	when a
       large number of directories are present in the search path. This	 hash-
       ing mechanism is	not used:

       1.  If hashing is turned	explicitly off via unhash.

       2.  If the shell	was given a -f argument.

       3.  For	each  directory	 component of path which does not begin	with a
	   `/'.

       4.  If the command contains a `/'.

       In the above four cases the shell concatenates each  component  of  the
       path  vector  with the given command name to form a path	name of	a file
       which it	then attempts to execute it. If	execution is  successful,  the
       search stops.

       If  the	file  has  execute permissions but is not an executable	to the
       system (i.e., it	is neither an executable  binary  nor  a  script  that
       specifies  its interpreter), then it is assumed to be a file containing
       shell commands and a new	shell is spawned to read it.  The  shell  spe-
       cial  alias  may	 be set	to specify an interpreter other	than the shell
       itself.

       On systems which	do not understand the `#!' script interpreter  conven-
       tion  the  shell	 may  be compiled to emulate it; see the version shell
       variable.  If so, the shell checks the first line of the	file to	see if
       it  is of the form `#!interpreter arg ...'.  If it is, the shell	starts
       interpreter with	the given args and feeds the file to  it  on  standard
       input.

   Input/output
       The  standard  input and	standard output	of a command may be redirected
       with the	following syntax:

       < name  Open file name (which is	first variable,	command	 and  filename
	       expanded) as the	standard input.
       << word Read  the  shell	input up to a line which is identical to word.
	       word is not subjected to	variable, filename or command  substi-
	       tution, and each	input line is compared to word before any sub-
	       stitutions are done on this input line.	Unless a quoting  `\',
	       `"',  `'	 or ``'	appears	in word	variable and command substitu-
	       tion is performed on the	intervening  lines,  allowing  `\'  to
	       quote  `$',  `\'	 and ``'.  Commands which are substituted have
	       all blanks, tabs, and newlines preserved, except	for the	 final
	       newline	which  is dropped.  The	resultant text is placed in an
	       anonymous temporary file	which is given to the command as stan-
	       dard input.
       > name
       _! name
       __ name
       __! name
	       The file	name is	used as	standard output.  If the file does not
	       exist then it is	created; if the	file exists, it	is  truncated,
	       its previous contents being lost.

	       If  the shell variable noclobber	is set,	then the file must not
	       exist or	be a character	special	 file  (e.g.,  a  terminal  or
	       `/dev/null')  or	an error results.  This	helps prevent acciden-
	       tal destruction of files.  In this case the `!'	forms  can  be
	       used to suppress	this check.

	       The  forms  involving  `&' route	the diagnostic output into the
	       specified file as well as the standard  output.	 name  is  ex-
	       panded in the same way as `<' input filenames are.
       >> name
       ___ name
       __! name
       ___! name
	       Like  `>', but appends output to	the end	of name.  If the shell
	       variable	noclobber is set, then it is an	error for the file not
	       to exist, unless	one of the `!' forms is	given.

       A  command  receives  the environment in	which the shell	was invoked as
       modified	by the input-output parameters and the presence	of the command
       in  a pipeline.	Thus, unlike some previous shells, commands run	from a
       file of shell commands have no access to	the text of  the  commands  by
       default;	 rather	they receive the original standard input of the	shell.
       The `<<'	mechanism should be used to present inline data.  This permits
       shell command scripts to	function as components of pipelines and	allows
       the shell to block read its input.  Note	that the default standard  in-
       put for a command run detached is not the empty file /dev/null, but the
       original	standard input of the shell.  If this is a terminal and	if the
       process attempts	to read	from the terminal, then	the process will block
       and the user will be notified (see Jobs).

       Diagnostic output may be	directed through a pipe	with the standard out-
       put.  Simply use	the form `|&' rather than just `|'.

       The  shell  cannot  presently  redirect	diagnostic output without also
       redirecting standard output, but	`(command  >  output-file)  >&	error-
       file'  is often an acceptable workaround.  Either output-file or	error-
       file may	be `/dev/tty' to send output to	the terminal.

   Features
       Having described	how the	shell accepts,	parses	and  executes  command
       lines, we now turn to a variety of its useful features.

   Control flow
       The  shell  contains a number of	commands which can be used to regulate
       the flow	of control in command files (shell scripts)  and  (in  limited
       but  useful  ways)  from	terminal input.	 These commands	all operate by
       forcing the shell to reread or skip in its input	and, due to the	imple-
       mentation, restrict the placement of some of the	commands.

       The  foreach, switch, and while statements, as well as the if-then-else
       form of the if statement, require that the major	keywords appear	 in  a
       single simple command on	an input line as shown below.

       If  the shell's input is	not seekable, the shell	buffers	up input when-
       ever a loop is being read and performs seeks in this internal buffer to
       accomplish the rereading	implied	by the loop.  (To the extent that this
       allows, backward	gotos will succeed on non-seekable inputs.)

   Expressions
       The if, while and exit builtin commands use expressions with  a	common
       syntax.	 The expressions can include any of the	operators described in
       the next	three sections.	 Note that the @ builtin  command  (q.v.)  has
       its own separate	syntax.

   Logical, arithmetical and comparison	operators
       These operators are similar to those of C and have the same precedence.
       They include

	   ||  &&  |  ^	 &  ==	!=  =~	!~  <=	>=
	   <  >	<<  >>	+  -  *	 /  %  !  ~  (	)

       Here the	precedence increases to	the right, `=='	`!='  `=~'  and	 `!~',
       `<='  `>=' `<' and `>', `<<' and	`>>', `+' and `-', `*' `/' and `%' be-
       ing, in groups, at the same level.  The `==' `!=' `=~' and `!~'	opera-
       tors compare their arguments as strings;	all others operate on numbers.
       The operators `=~' and `!~' are like `!='  and  `=='  except  that  the
       right  hand  side is a glob-pattern (see	Filename substitution) against
       which the left hand operand is matched.	This reduces the need for  use
       of  the switch builtin command in shell scripts when all	that is	really
       needed is pattern matching.

       Null or missing arguments are considered	`0'.  The results of  all  ex-
       pressions  are  strings,	which represent	decimal	numbers.  It is	impor-
       tant to note that no two	components of an expression can	appear in  the
       same  word; except when adjacent	to components of expressions which are
       syntactically significant to the	parser (`&' `|'	`<' `>'	`(' `)')  they
       should be surrounded by spaces.

   Command exit	status
       Commands	 can be	executed in expressions	and their exit status returned
       by enclosing them in braces (`{}').  Remember that the braces should be
       separated  from the words of the	command	by spaces.  Command executions
       succeed,	returning true,	i.e., `1', if the command exits	with status 0,
       otherwise they fail, returning false, i.e., `0'.	 If more detailed sta-
       tus information is required then	the command should be executed outside
       of an expression	and the	status shell variable examined.

   File	inquiry	operators
       Some  of	 these operators perform true/false tests on files and related
       objects.	 They are of the form -op file,	where op is one	of

	   r   Read access
	   w   Write access
	   x   Execute access
	   X   Executable in the path or shell builtin,	e.g., `-X ls' and  `-X
	       ls-F' are generally true, but `-X /bin/ls' is not (+)
	   e   Existence
	   o   Ownership
	   z   Zero size
	   s   Non-zero	size (+)
	   f   Plain file
	   d   Directory
	   l   Symbolic	link (+) *
	   b   Block special file (+)
	   c   Character special file (+)
	   p   Named pipe (fifo) (+) *
	   S   Socket special file (+) *
	   u   Set-user-ID bit is set (+)
	   g   Set-group-ID bit	is set (+)
	   k   Sticky bit is set (+)
	   t   file  (which  must be a digit) is an open file descriptor for a
	       terminal	device (+)
	   R   Has been	migrated (convex only) (+)
	   L   Applies subsequent operators in a multiple-operator test	 to  a
	       symbolic	 link rather than to the file to which the link	points
	       (+) *

       file is command and filename expanded and then tested to	see if it  has
       the specified relationship to the real user.  If	file does not exist or
       is inaccessible or, for the operators indicated by `*', if  the	speci-
       fied file type does not exist on	the current system, then all enquiries
       return false, i.e., `0'.

       These operators may be combined for conciseness:	`-xy file' is  equiva-
       lent  to	`-x file && -y file'.  (+) For example,	`-fx' is true (returns
       `1') for	plain executable files,	but not	for directories.

       L may be	used in	a multiple-operator test to apply subsequent operators
       to  a  symbolic	link rather than to the	file to	which the link points.
       For example, `-lLo' is true for links owned by the invoking user.   Lr,
       Lw  and	Lx are always true for links and false for non-links.  L has a
       different meaning when it is the	last operator in  a  multiple-operator
       test; see below.

       It is possible but not useful, and sometimes misleading,	to combine op-
       erators which expect file to be a file with  operators  which  do  not,
       (e.g., X	and t).	 Following L with a non-file operator can lead to par-
       ticularly strange results.

       Other operators return other information, i.e., not just	 `0'  or  `1'.
       (+) They	have the same format as	before;	op may be one of

	   A	   Last	 file  access time, as the number of seconds since the
		   epoch
	   A:	   Like	A, but in timestamp format, e.g., `Fri May 14 16:36:10
		   1993'
	   M	   Last	file modification time
	   M:	   Like	M, but in timestamp format
	   C	   Last	inode modification time
	   C:	   Like	C, but in timestamp format
	   D	   Device number
	   I	   Inode number
	   F	   Composite file identifier, in the form device:inode
	   L	   The name of the file	pointed	to by a	symbolic link
	   N	   Number of (hard) links
	   P	   Permissions,	in octal, without leading zero
	   P:	   Like	P, with	leading	zero
	   Pmode   Equivalent  to  `-P file & mode', e.g., `-P22 file' returns
		   `22'	if file	is writable by group and  other,  `20'	if  by
		   group only, and `0' if by neither
	   Pmode:  Like	Pmode, with leading zero
	   U	   Numeric userid
	   U:	   Username, or	the numeric userid if the username is unknown
	   G	   Numeric groupid
	   G:	   Groupname,  or  the numeric groupid if the groupname	is un-
		   known
	   Z	   Size, in bytes

       Only one	of these operators may appear in a multiple-operator test, and
       it must be the last.  Note that L has a different meaning at the	end of
       and elsewhere in	a multiple-operator test.  Because `0' is a valid  re-
       turn  value  for	 many  of these	operators, they	do not return `0' when
       they fail: most return `-1', and	F returns `:'.

       If the shell is compiled	with POSIX  defined  (see  the	version	 shell
       variable), the result of	a file inquiry is based	on the permission bits
       of the file and not on the result of the	access(2)  system  call.   For
       example,	if one tests a file with -w whose permissions would ordinarily
       allow writing but which is on a file system mounted read-only, the test
       will succeed in a POSIX shell but fail in a non-POSIX shell.

       File  inquiry operators can also	be evaluated with the filetest builtin
       command (q.v.) (+).

   Jobs
       The shell associates a job with each pipeline.  It  keeps  a  table  of
       current jobs, printed by	the jobs command, and assigns them small inte-
       ger numbers.  When a job	is started asynchronously with `&', the	 shell
       prints a	line which looks like

	   [1] 1234

       indicating that the job which was started asynchronously	was job	number
       1 and had one (top-level) process, whose	process	id was 1234.

       If you are running a job	and wish to do something else you may hit  the
       suspend	key  (usually  `^Z'), which sends a STOP signal	to the current
       job.  The shell will then normally indicate that	the job	has been `Sus-
       pended'	and  print  another prompt.  If	the listjobs shell variable is
       set, all	jobs will be listed like the jobs builtin command;  if	it  is
       set  to `long' the listing will be in long format, like `jobs -l'.  You
       can then	manipulate the state of	the suspended job.  You	can put	it  in
       the  ``background''  with the bg	command	or run some other commands and
       eventually bring	the job	back into the ``foreground''  with  fg.	  (See
       also  the  run-fg-editor	 editor	command.)  A `^Z' takes	effect immedi-
       ately and is like an interrupt in that pending output and unread	 input
       are  discarded  when  it	is typed.  The wait builtin command causes the
       shell to	wait for all background	jobs to	complete.

       The `^]'	key sends a delayed suspend signal, which does not generate  a
       STOP signal until a program attempts to read(2) it, to the current job.
       This can	usefully be typed ahead	when you have prepared	some  commands
       for  a job which	you wish to stop after it has read them.  The `^Y' key
       performs	this function in csh(1); in tcsh, `^Y' is an editing  command.
       (+)

       A  job  being  run in the background stops if it	tries to read from the
       terminal.  Background jobs are normally allowed to produce output,  but
       this  can  be disabled by giving	the command `stty tostop'.  If you set
       this tty	option,	then background	jobs will stop when they try  to  pro-
       duce output like	they do	when they try to read input.

       There  are  several  ways to refer to jobs in the shell.	 The character
       `%' introduces a	job name.  If you wish to refer	to job number  1,  you
       can  name  it  as `%1'.	Just naming a job brings it to the foreground;
       thus `%1' is a synonym for `fg %1', bringing job	1 back into the	 fore-
       ground.	Similarly, saying `%1 &' resumes job 1 in the background, just
       like `bg	%1'.  A	job can	also be	named by an unambiguous	prefix of  the
       string  typed  in to start it: `%ex' would normally restart a suspended
       ex(1) job, if there were	only one suspended job whose name  began  with
       the  string  `ex'.   It is also possible	to say `%?string' to specify a
       job whose text contains string, if there	is only	one such job.

       The shell maintains a notion of the current and previous	jobs.  In out-
       put  pertaining	to  jobs, the current job is marked with a `+' and the
       previous	job with a `-'.	 The abbreviations `%+', `%', and (by  analogy
       with the	syntax of the history mechanism) `%%' all refer	to the current
       job, and	`%-' refers to the previous job.

       The job control mechanism requires that the stty(1) option `new'	be set
       on  some	systems.  It is	an artifact from a `new' implementation	of the
       tty driver which	allows generation of  interrupt	 characters  from  the
       keyboard	 to tell jobs to stop.	See stty(1) and	the setty builtin com-
       mand for	details	on setting options in the new tty driver.

   Status reporting
       The shell learns	immediately whenever a process changes state.  It nor-
       mally  informs  you  whenever  a	job becomes blocked so that no further
       progress	is possible, but only right before it prints a	prompt.	  This
       is  done	so that	it does	not otherwise disturb your work.  If, however,
       you set the shell variable notify, the shell will  notify  you  immedi-
       ately  of  changes of status in background jobs.	 There is also a shell
       command notify which marks a single process so that its status  changes
       will  be	 immediately  reported.	  By  default notify marks the current
       process;	simply say `notify' after starting a background	 job  to  mark
       it.

       When  you  try  to  leave the shell while jobs are stopped, you will be
       warned that `There are suspended	jobs.' You may use the jobs command to
       see  what  they	are.  If you do	this or	immediately try	to exit	again,
       the shell will not warn you a second time, and the suspended jobs  will
       be terminated.

   Automatic, periodic and timed events	(+)
       There are various ways to run commands and take other actions automati-
       cally at	various	times in the ``life cycle'' of the  shell.   They  are
       summarized  here, and described in detail under the appropriate Builtin
       commands, Special shell variables and Special aliases.

       The sched builtin command puts commands in a scheduled-event  list,  to
       be executed by the shell	at a given time.

       The  beepcmd,  cwdcmd,  periodic,  precmd,  postcmd, and	jobcmd Special
       aliases can be set, respectively, to execute commands  when  the	 shell
       wants  to ring the bell,	when the working directory changes, every tpe-
       riod minutes, before each prompt, before	each  command  gets  executed,
       after  each  command  gets  executed,  and  when	a job is started or is
       brought into the	foreground.

       The autologout shell variable can be set	to log out or lock  the	 shell
       after a given number of minutes of inactivity.

       The mail	shell variable can be set to check for new mail	periodically.

       The  printexitvalue  shell variable can be set to print the exit	status
       of commands which exit with a status other than zero.

       The rmstar shell	variable can be	set to ask the user, when  `rm	*'  is
       typed, if that is really	what was meant.

       The  time shell variable	can be set to execute the time builtin command
       after the completion of any process that	takes more than	a given	number
       of CPU seconds.

       The  watch  and	who shell variables can	be set to report when selected
       users log in or out, and	the log	builtin	command	reports	on those users
       at any time.

   Native Language System support (+)
       The  shell  is  eight  bit clean	(if so compiled; see the version shell
       variable) and thus supports character  sets  needing  this  capability.
       NLS  support differs depending on whether or not	the shell was compiled
       to use the system's NLS (again, see version).  In  either  case,	 7-bit
       ASCII  is the default character code (e.g., the classification of which
       characters are  printable)  and	sorting,  and  changing	 the  LANG  or
       LC_CTYPE	 environment  variables	causes a check for possible changes in
       these respects.

       When using the system's NLS, the	setlocale(3) function is called	to de-
       termine	appropriate character code/classification and sorting (e.g., a
       'en_CA.UTF-8' would yield "UTF-8" as a character	code).	This  function
       typically  examines  the	LANG and LC_CTYPE environment variables; refer
       to the system documentation for further details.	 When  not  using  the
       system's	 NLS,  the  shell simulates it by assuming that	the ISO	8859-1
       character set is	used whenever either of	the LANG  and  LC_CTYPE	 vari-
       ables are set, regardless of their values.  Sorting is not affected for
       the simulated NLS.

       In addition, with both real and simulated NLS, all printable characters
       in  the range \200-\377,	i.e., those that have M-char bindings, are au-
       tomatically rebound to self-insert-command.  The	corresponding  binding
       for  the	escape-char sequence, if any, is left alone.  These characters
       are not rebound if the NOREBIND environment variable is set.  This  may
       be  useful  for the simulated NLS or a primitive	real NLS which assumes
       full ISO	8859-1.	 Otherwise, all	M-char bindings	in the range \240-\377
       are  effectively	 undone.   Explicitly rebinding	the relevant keys with
       bindkey is of course still possible.

       Unknown characters (i.e., those that are	neither	printable nor  control
       characters) are printed in the format \nnn.  If the tty is not in 8 bit
       mode, other 8 bit characters are	printed	by converting  them  to	 ASCII
       and  using  standout mode.  The shell never changes the 7/8 bit mode of
       the tty and tracks user-initiated changes of 7/8	bit mode.   NLS	 users
       (or, for	that matter, those who want to use a meta key) may need	to ex-
       plicitly	set the	tty in 8 bit mode through the appropriate stty(1) com-
       mand in,	e.g., the ~/.login file.

   OS variant support (+)
       A  number  of  new builtin commands are provided	to support features in
       particular operating systems.  All  are	described  in  detail  in  the
       Builtin commands	section.

       On  systems  that  support  TCF	(aix-ibm370,  aix-ps2),	 getspath  and
       setspath	get and	set the	system execution path, getxvers	 and  setxvers
       get  and	 set the experimental version prefix and migrate migrates pro-
       cesses between sites.  The jobs builtin prints the site on  which  each
       job is executing.

       Under BS2000, bs2cmd executes commands of the underlying	BS2000/OSD op-
       erating system.

       Under Domain/OS,	inlib adds shared libraries to	the  current  environ-
       ment, rootnode changes the rootnode and ver changes the systype.

       Under Mach, setpath is equivalent to Mach's setpath(1).

       Under Masscomp/RTU and Harris CX/UX, universe sets the universe.

       Under  Harris CX/UX, ucb	or att runs a command under the	specified uni-
       verse.

       Under Convex/OS,	warp prints or sets the	universe.

       The VENDOR, OSTYPE and MACHTYPE environment variables indicate  respec-
       tively  the  vendor,  operating system and machine type (microprocessor
       class or	machine	model) of the system on	which the shell	thinks	it  is
       running.	  These	are particularly useful	when sharing one's home	direc-
       tory between several types of machines; one can,	for example,

	   set path = (~/bin.$MACHTYPE /usr/ucb	/bin /usr/bin .)

       in one's	~/.login and put executables compiled for each machine in  the
       appropriate directory.

       The  version shell variable indicates what options were chosen when the
       shell was compiled.

       Note also the newgrp builtin, the afsuser and  echo_style  shell	 vari-
       ables  and  the	system-dependent  locations of the shell's input files
       (see FILES).

   Signal handling
       Login shells ignore interrupts when reading the	file  ~/.logout.   The
       shell  ignores quit signals unless started with -q.  Login shells catch
       the terminate signal, but non-login shells inherit the terminate	behav-
       ior  from their parents.	 Other signals have the	values which the shell
       inherited from its parent.

       In shell	scripts, the shell's handling of interrupt and terminate  sig-
       nals  can be controlled with onintr, and	its handling of	hangups	can be
       controlled with hup and nohup.

       The shell exits on a hangup (see	also the logout	shell  variable).   By
       default,	 the shell's children do too, but the shell does not send them
       a hangup	when it	exits.	hup arranges for the shell to send a hangup to
       a child when it exits, and nohup	sets a child to	ignore hangups.

   Terminal management (+)
       The  shell  uses	 three	different  sets	 of  terminal (``tty'')	modes:
       `edit', used when editing, `quote', used	when quoting  literal  charac-
       ters,  and  `execute',  used  when executing commands.  The shell holds
       some settings in	each mode constant, so commands	which leave the	tty in
       a  confused  state  do  not  interfere  with the	shell.	The shell also
       matches changes in the speed and	padding	of the tty.  The list  of  tty
       modes  that  are	 kept  constant	 can be	examined and modified with the
       setty builtin.  Note that although the editor uses CBREAK mode (or  its
       equivalent), it takes typed-ahead characters anyway.

       The echotc, settc and telltc commands can be used to manipulate and de-
       bug terminal capabilities from the command line.

       On systems that support SIGWINCH	or SIGWINDOW, the shell	adapts to win-
       dow  resizing automatically and adjusts the environment variables LINES
       and COLUMNS if set.  If the environment variable	TERMCAP	 contains  li#
       and co# fields, the shell adjusts them to reflect the new window	size.

REFERENCE
       The  next sections of this manual describe all of the available Builtin
       commands, Special aliases and Special shell variables.

   Builtin commands
       %job    A synonym for the fg builtin command.

       %job &  A synonym for the bg builtin command.

       :       Does nothing, successfully.

       @
       @ name =	expr
       @ name[index] = expr
       @ name++|--
       @ name[index]++|--
	       The first form prints the values	of all shell variables.

	       The second form assigns the value of expr to name.   The	 third
	       form  assigns  the  value  of expr to the index'th component of
	       name; both name and its index'th	component must already exist.

	       expr may	contain	the operators `*', `+',	etc.,  as  in  C.   If
	       expr  contains  `<',  `>', `&' or `' then at least that part of
	       expr must be placed within `()'.	 Note that the syntax of  expr
	       has nothing to do with that described under Expressions.

	       The fourth and fifth forms increment (`++') or decrement	(`--')
	       name or its index'th component.

	       The space between `@' and name is required.  The	spaces between
	       name and	`=' and	between	`=' and	expr are optional.  Components
	       of expr must be separated by spaces.

       alias [name [wordlist]]
	       Without arguments, prints all aliases.  With name,  prints  the
	       alias  for  name.   With	name and wordlist, assigns wordlist as
	       the alias of name.  wordlist is command	and  filename  substi-
	       tuted.  name may	not be `alias' or `unalias'.  See also the un-
	       alias builtin command.

       alloc   Shows the amount	of dynamic memory acquired, broken  down  into
	       used  and  free	memory.	  With an argument shows the number of
	       free and	used blocks in each  size  category.   The  categories
	       start at	size 8 and double at each step.	 This command's	output
	       may vary	across system types, because systems  other  than  the
	       VAX may use a different memory allocator.

       bg [%job	...]
	       Puts  the  specified  jobs  (or,	without	arguments, the current
	       job) into the background, continuing each  if  it  is  stopped.
	       job may be a number, a string, `', `%', `+' or `-' as described
	       under Jobs.

       bindkey [-l|-d|-e|-v|-u]	(+)
       bindkey [-a] [-b] [-k] [-r] [--]	key (+)
       bindkey [-a] [-b] [-k] [-c|-s] [--] key command (+)
	       Without options,	the first form lists all bound	keys  and  the
	       editor  command	to  which each is bound, the second form lists
	       the editor command to which key is bound	 and  the  third  form
	       binds the editor	command	command	to key.	 Options include:

	       -l  Lists all editor commands and a short description of	each.
	       -d  Binds all keys to the standard bindings for the default ed-
		   itor.
	       -e  Binds all keys to the standard GNU Emacs-like bindings.
	       -v  Binds all keys to the standard vi(1)-like bindings.
	       -a  Lists or changes key-bindings in the	alternative  key  map.
		   This	is the key map used in vi command mode.
	       -b  key	is interpreted as a control character written ^charac-
		   ter (e.g., `^A') or C-character (e.g., `C-A'), a meta char-
		   acter  written  M-character	(e.g.,	`M-A'),	a function key
		   written F-string (e.g., `F-string'),	or an extended	prefix
		   key written X-character (e.g., `X-A').
	       -k  key	is interpreted as a symbolic arrow key name, which may
		   be one of `down', `up', `left' or `right'.
	       -r  Removes key's binding.  Be careful: `bindkey	-r'  does  not
		   bind	key to self-insert-command (q.v.), it unbinds key com-
		   pletely.
	       -c  command is interpreted as a builtin or external command in-
		   stead of an editor command.
	       -s  command  is taken as	a literal string and treated as	termi-
		   nal input when key is typed.	 Bound	keys  in  command  are
		   themselves reinterpreted, and this continues	for ten	levels
		   of interpretation.
	       --  Forces a break from option processing, so the next word  is
		   taken as key	even if	it begins with '-'.
	       -u (or any invalid option)
		   Prints a usage message.

	       key  may	 be  a	single character or a string.  If a command is
	       bound to	a string, the first character of the string  is	 bound
	       to  sequence-lead-in and	the entire string is bound to the com-
	       mand.

	       Control characters in key can be	literal	(they can be typed  by
	       preceding  them with the	editor command quoted-insert, normally
	       bound to	`^V') or written caret-character  style,  e.g.,	 `^A'.
	       Delete is written `^?'  (caret-question mark).  key and command
	       can contain backslashed escape sequences	(in the	style of  Sys-
	       tem V echo(1)) as follows:

		   \a	   Bell
		   \b	   Backspace
		   \e	   Escape
		   \f	   Form	feed
		   \n	   Newline
		   \r	   Carriage return
		   \t	   Horizontal tab
		   \v	   Vertical tab
		   \nnn	   The ASCII character corresponding to	the octal num-
			   ber nnn

	       `\' nullifies the special meaning of the	 following  character,
	       if it has any, notably `\' and `^'.

       bs2cmd bs2000-command (+)
	       Passes bs2000-command to	the BS2000 command interpreter for ex-
	       ecution.	Only non-interactive commands can be executed, and  it
	       is  not	possible to execute any	command	that would overlay the
	       image of	the current process, like /EXECUTE or /CALL-PROCEDURE.
	       (BS2000 only)

       break   Causes execution	to resume after	the end	of the nearest enclos-
	       ing foreach or while.  The remaining commands  on  the  current
	       line  are  executed.   Multi-level  breaks are thus possible by
	       writing them all	on one line.

       breaksw Causes a	break from a switch, resuming after the	endsw.

       builtins	(+)
	       Prints the names	of all builtin commands.

       bye (+) A synonym for the logout	builtin	command.   Available  only  if
	       the shell was so	compiled; see the version shell	variable.

       case label:
	       A label in a switch statement as	discussed below.

       cd [-p] [-l] [-n|-v] [name]
	       If  a  directory	name is	given, changes the shell's working di-
	       rectory to name.	 If not, changes to home.  If name is  `-'  it
	       is  interpreted	as  the	 previous working directory (see Other
	       substitutions).	(+) If name is not a subdirectory of the  cur-
	       rent  directory	(and  does not begin with `/', `./' or `../'),
	       each component of the variable cdpath is	checked	to see	if  it
	       has  a  subdirectory name.  Finally, if all else	fails but name
	       is a shell variable whose value begins with `/',	then  this  is
	       tried to	see if it is a directory.

	       With -p,	prints the final directory stack, just like dirs.  The
	       -l, -n and -v flags have	the same effect	on cd as on dirs,  and
	       they imply -p.  (+)

	       See also	the implicitcd shell variable.

       chdir   A synonym for the cd builtin command.

       complete	[command [word/pattern/list[:select]/[[suffix]/] ...]] (+)
	       Without	arguments, lists all completions.  With	command, lists
	       completions for command.	 With command and word	etc.,  defines
	       completions.

	       command may be a	full command name or a glob-pattern (see File-
	       name substitution).  It can begin with  `-'  to	indicate  that
	       completion should be used only when command is ambiguous.

	       word specifies which word relative to the current word is to be
	       completed, and may be one of the	following:

		   c   Current-word completion.	  pattern  is  a  glob-pattern
		       which  must  match the beginning	of the current word on
		       the command line.  pattern is ignored  when  completing
		       the current word.
		   C   Like  c,	 but includes pattern when completing the cur-
		       rent word.
		   n   Next-word completion.  pattern is a glob-pattern	 which
		       must  match  the	 beginning of the previous word	on the
		       command line.
		   N   Like n, but must	match the beginning of	the  word  two
		       before the current word.
		   p   Position-dependent  completion.	 pattern  is a numeric
		       range, with the same syntax used	to index  shell	 vari-
		       ables, which must include the current word.

	       list,  the list of possible completions,	may be one of the fol-
	       lowing:

		   a	   Aliases
		   b	   Bindings (editor commands)
		   c	   Commands (builtin or	external commands)
		   C	   External commands which  begin  with	 the  supplied
			   path	prefix
		   d	   Directories
		   D	   Directories which begin with	the supplied path pre-
			   fix
		   e	   Environment variables
		   f	   Filenames
		   F	   Filenames which begin with the supplied path	prefix
		   g	   Groupnames
		   j	   Jobs
		   l	   Limits
		   n	   Nothing
		   s	   Shell variables
		   S	   Signals
		   t	   Plain (``text'') files
		   T	   Plain (``text'') files which	begin  with  the  sup-
			   plied path prefix
		   v	   Any variables
		   u	   Usernames
		   x	   Like	 n,  but  prints  select  when list-choices is
			   used.
		   X	   Completions
		   $var	   Words from the variable var
		   (...)   Words from the given	list
		   `...`   Words from the output of command

	       select is an optional glob-pattern.  If given, words from  only
	       list  that  match  select  are considered and the fignore shell
	       variable	is ignored.  The last three types  of  completion  may
	       not  have a select pattern, and x uses select as	an explanatory
	       message when the	list-choices editor command is used.

	       suffix is a single character to be  appended  to	 a  successful
	       completion.  If null, no	character is appended.	If omitted (in
	       which case the fourth delimiter can also	be omitted),  a	 slash
	       is appended to directories and a	space to other words.

	       command	invoked	 from `...` version has	additional environment
	       variable	set, the variable name is  COMMAND_LINE	 and  contains
	       (as  its	name indicates)	contents of the	current	(already typed
	       in) command line. One can  examine  and	use  contents  of  the
	       COMMAND_LINE  variable  in  her custom script to	build more so-
	       phisticated completions (see completion for svn(1) included  in
	       this package).

	       Now  for	some examples.	Some commands take only	directories as
	       arguments, so there's no	point completing plain files.

		   > complete cd 'p/1/d/'

	       completes only the first	word following `cd' (`p/1') with a di-
	       rectory.	  p-type  completion  can  also	be used	to narrow down
	       command completion:

		   > co[^D]
		   complete compress
		   > complete -co* 'p/0/(compress)/'
		   > co[^D]
		   > compress

	       This completion completes commands (words in position 0,	`p/0')
	       which  begin with `co' (thus matching `co*') to `compress' (the
	       only word in the	list).	The leading `-'	 indicates  that  this
	       completion is to	be used	with only ambiguous commands.

		   > complete find 'n/-user/u/'

	       is  an example of n-type	completion.  Any word following	`find'
	       and immediately following `-user' is completed from the list of
	       users.

		   > complete cc 'c/-I/d/'

	       demonstrates  c-type  completion.   Any word following `cc' and
	       beginning with `-I' is completed	as a directory.	 `-I'  is  not
	       taken as	part of	the directory because we used lowercase	c.

	       Different lists are useful with different commands.

		   > complete alias 'p/1/a/'
		   > complete man 'p/*/c/'
		   > complete set 'p/1/s/'
		   > complete true 'p/1/x:Truth	has no options./'

	       These complete words following `alias' with aliases, `man' with
	       commands, and `set' with	shell variables.  `true' doesn't  have
	       any options, so x does nothing when completion is attempted and
	       prints `Truth has no  options.'	when  completion  choices  are
	       listed.

	       Note  that  the	man example, and several other examples	below,
	       could just as well have used 'c/*' or 'n/*' as 'p/*'.

	       Words can be completed from a variable evaluated	at  completion
	       time,

		   > complete ftp 'p/1/$hostnames/'
		   > set hostnames = (rtfm.mit.edu tesla.ee.cornell.edu)
		   > ftp [^D]
		   rtfm.mit.edu	tesla.ee.cornell.edu
		   > ftp [^C]
		   >   set   hostnames	=  (rtfm.mit.edu  tesla.ee.cornell.edu
		   uunet.uu.net)
		   > ftp [^D]
		   rtfm.mit.edu	tesla.ee.cornell.edu uunet.uu.net

	       or from a command run at	completion time:

		   > complete kill 'p/*/`ps | awk \{print\ \$1\}`/'
		   > kill -9 [^D]
		   23113 23377 23380 23406 23429 23529 23530 PID

	       Note that the complete command does not itself quote its	 argu-
	       ments,  so  the	braces,	 space and `$' in `{print $1}' must be
	       quoted explicitly.

	       One command can have multiple completions:

		   > complete dbx 'p/2/(core)/'	'p/*/c/'

	       completes the second argument to	`dbx' with the word `core' and
	       all  other  arguments  with commands.  Note that	the positional
	       completion is specified before the next-word  completion.   Be-
	       cause  completions  are	evaluated  from	 left to right,	if the
	       next-word completion were specified first it would always match
	       and the positional completion would never be executed.  This is
	       a common	mistake	when defining a	completion.

	       The select pattern is useful when a command  takes  files  with
	       only particular forms as	arguments.  For	example,

		   > complete cc 'p/*/f:*.[cao]/'

	       completes `cc' arguments	to files ending	in only	`.c', `.a', or
	       `.o'.  select can also exclude files, using negation of a glob-
	       pattern	as  described  under Filename substitution.  One might
	       use

		   > complete rm 'p/*/f:^*.{c,h,cc,C,tex,1,man,l,y}/'

	       to exclude precious  source  code  from	`rm'  completion.   Of
	       course,	one  could still type excluded names manually or over-
	       ride the	completion mechanism using  the	 complete-word-raw  or
	       list-choices-raw	editor commands	(q.v.).

	       The  `C', `D', `F' and `T' lists	are like `c', `d', `f' and `t'
	       respectively, but they use the select argument in  a  different
	       way:  to	restrict completion to files beginning with a particu-
	       lar path	prefix.	 For example, the Elm mail program uses	`=' as
	       an abbreviation for one's mail directory.  One might use

		   > complete elm c@=@F:$HOME/Mail/@

	       to  complete  `elm  -f =' as if it were `elm -f ~/Mail/'.  Note
	       that we used `@'	instead	of `/' to avoid	confusion with the se-
	       lect  argument, and we used `$HOME' instead of `~' because home
	       directory substitution works at only the	beginning of a word.

	       suffix is used to add a nonstandard suffix (not	space  or  `/'
	       for directories)	to completed words.

		   > complete finger 'c/*@/$hostnames/'	'p/1/u/@'

	       completes arguments to `finger' from the	list of	users, appends
	       an `@', and then	completes after	the `@'	from  the  `hostnames'
	       variable.   Note	 again	the order in which the completions are
	       specified.

	       Finally,	here's a complex example for inspiration:

		   > complete find \
		   'n/-name/f/'	'n/-newer/f/' 'n/-{,n}cpio/f/' \
		   'n/-exec/c/'	'n/-ok/c/' 'n/-user/u/'	\
		   'n/-group/g/' 'n/-fstype/(nfs 4.2)/'	\
		   'n/-type/(b c d f l p s)/' \
		   'c/-/(name newer cpio ncpio exec ok user \
		   group fstype	type atime ctime depth inum \
		   ls mtime nogroup nouser perm	print prune \
		   size	xdev)/'	\
		   'p/*/d/'

	       This completes words following `-name',	`-newer',  `-cpio'  or
	       `ncpio'	(note  the pattern which matches both) to files, words
	       following `-exec' or `-ok' to commands, words following	`user'
	       and  `group' to users and groups	respectively and words follow-
	       ing `-fstype' or	`-type'	to members of  the  given  lists.   It
	       also  completes	the  switches  themselves  from	the given list
	       (note the use of	c-type completion) and completes anything  not
	       otherwise completed to a	directory.  Whew.

	       Remember	 that  programmed  completions are ignored if the word
	       being completed is a tilde substitution (beginning with `~') or
	       a  variable  (beginning with `$').  complete is an experimental
	       feature,	and the	syntax may change in future  versions  of  the
	       shell.  See also	the uncomplete builtin command.

       continue
	       Continues  execution of the nearest enclosing while or foreach.
	       The rest	of the commands	on the current line are	executed.

       default:
	       Labels the default case in a switch statement.  It should  come
	       after all case labels.

       dirs [-l] [-n|-v]
       dirs -S|-L [filename] (+)
       dirs -c (+)
	       The  first  form	 prints	 the  directory	stack.	The top	of the
	       stack is	at the left and	the first directory in	the  stack  is
	       the  current  directory.	 With -l, `~' or `~name' in the	output
	       is expanded explicitly to home or the pathname of the home  di-
	       rectory for user	name.  (+) With	-n, entries are	wrapped	before
	       they reach the edge of the screen.  (+) With  -v,  entries  are
	       printed	one  per line, preceded	by their stack positions.  (+)
	       If more than one	of -n or -v is given, -v takes precedence.  -p
	       is accepted but does nothing.

	       With  -S, the second form saves the directory stack to filename
	       as a series of cd and  pushd  commands.	 With  -L,  the	 shell
	       sources	filename,  which  is presumably	a directory stack file
	       saved by	the -S option or the savedirs  mechanism.   In	either
	       case,  dirsfile is used if filename is not given	and ~/.cshdirs
	       is used if dirsfile is unset.

	       Note that login shells  do  the	equivalent  of	`dirs  -L'  on
	       startup and, if savedirs	is set,	`dirs -S' before exiting.  Be-
	       cause only ~/.tcshrc is	normally  sourced  before  ~/.cshdirs,
	       dirsfile	should be set in ~/.tcshrc rather than ~/.login.

	       The last	form clears the	directory stack.

       echo [-n] word ...
	       Writes  each  word to the shell's standard output, separated by
	       spaces and terminated with a  newline.	The  echo_style	 shell
	       variable	 may  be  set to emulate (or not) the flags and	escape
	       sequences of the	BSD and/or System  V  versions	of  echo;  see
	       echo(1).

       echotc [-sv] arg	... (+)
	       Exercises  the  terminal	capabilities (see termcap(5)) in args.
	       For example, 'echotc home' sends	the cursor to the  home	 posi-
	       tion,  'echotc  cm  3  10' sends	it to column 3 and row 10, and
	       'echotc ts 0; echo "This	is a test."; echotc fs'	 prints	 "This
	       is a test."  in the status line.

	       If arg is 'baud', 'cols', 'lines', 'meta' or 'tabs', prints the
	       value of	that capability	("yes" or  "no"	 indicating  that  the
	       terminal	does or	does not have that capability).	 One might use
	       this to make the	output from a shell  script  less  verbose  on
	       slow  terminals,	or limit command output	to the number of lines
	       on the screen:

		   > set history=`echotc lines`
		   > @ history--

	       Termcap strings may contain wildcards which will	not echo  cor-
	       rectly.	 One  should  use  double  quotes when setting a shell
	       variable	to a terminal capability string, as in	the  following
	       example that places the date in the status line:

		   > set tosl="`echotc ts 0`"
		   > set frsl="`echotc fs`"
		   > echo -n "$tosl";date; echo	-n "$frsl"

	       With  -s,  nonexistent  capabilities  return  the  empty	string
	       rather than causing an error.  With -v, messages	are verbose.

       else
       end
       endif
       endsw   See the description of  the  foreach,  if,  switch,  and	 while
	       statements below.

       eval arg	...
	       Treats the arguments as input to	the shell and executes the re-
	       sulting command(s) in the context of the	current	 shell.	  This
	       is  usually used	to execute commands generated as the result of
	       command or variable substitution, because parsing occurs	before
	       these substitutions.  See tset(1) for a sample use of eval.

       exec command
	       Executes	the specified command in place of the current shell.

       exit [expr]
	       The shell exits either with the value of	the specified expr (an
	       expression, as described	under Expressions) or,	without	 expr,
	       with the	value 0.

       fg [%job	...]
	       Brings  the  specified jobs (or,	without	arguments, the current
	       job) into the foreground, continuing each  if  it  is  stopped.
	       job may be a number, a string, `', `%', `+' or `-' as described
	       under Jobs.  See	also the run-fg-editor editor command.

       filetest	-op file ... (+)
	       Applies op (which is a file inquiry operator as described under
	       File inquiry operators) to each file and	returns	the results as
	       a space-separated list.

       foreach name (wordlist)
       ...
       end     Successively sets the variable name to each member of  wordlist
	       and  executes the sequence of commands between this command and
	       the matching end.  (Both	foreach	and end	must appear  alone  on
	       separate	 lines.)   The builtin command continue	may be used to
	       continue	the loop prematurely and the builtin command break  to
	       terminate  it  prematurely.  When this command is read from the
	       terminal, the loop is read once prompting with `foreach?	'  (or
	       prompt2)	 before	 any  statements in the	loop are executed.  If
	       you make	a mistake typing in a loop at the terminal you can rub
	       it out.

       getspath	(+)
	       Prints the system execution path.  (TCF only)

       getxvers	(+)
	       Prints the experimental version prefix.	(TCF only)

       glob wordlist
	       Like  echo,  but	the `-n' parameter is not recognized and words
	       are delimited by	null characters	in  the	 output.   Useful  for
	       programs	 which wish to use the shell to	filename expand	a list
	       of words.

       goto word
	       word is filename	and command-substituted	to yield a  string  of
	       the  form `label'.  The shell rewinds its input as much as pos-
	       sible, searches for a line of the form `label:',	possibly  pre-
	       ceded  by  blanks  or  tabs, and	continues execution after that
	       line.

       hashstat
	       Prints a	statistics line	indicating how effective the  internal
	       hash table has been at locating commands	(and avoiding exec's).
	       An exec is attempted for	each component of the path  where  the
	       hash  function  indicates a possible hit, and in	each component
	       which does not begin with a `/'.

	       On machines without vfork(2), prints only the number  and  size
	       of hash buckets.

       history [-hTr] [n]
       history -S|-L|-M	[filename] (+)
       history -c (+)
	       The  first  form	 prints	the history event list.	 If n is given
	       only the	n most recent events are printed or saved.   With  -h,
	       the  history list is printed without leading numbers.  If -T is
	       specified, timestamps are printed also in comment form.	 (This
	       can be used to produce files suitable for loading with 'history
	       -L' or 'source -h'.)  With -r, the order	of  printing  is  most
	       recent first rather than	oldest first.

	       With  -S,  the  second form saves the history list to filename.
	       If the first word of the	savehist shell variable	is  set	 to  a
	       number,	at most	that many lines	are saved.  If the second word
	       of savehist is set to `merge', the history list is merged  with
	       the  existing history file instead of replacing it (if there is
	       one) and	sorted by time stamp.  (+) Merging is intended for  an
	       environment like	the X Window System with several shells	in si-
	       multaneous use.	Currently it succeeds  only  when  the	shells
	       quit nicely one after another.

	       With -L,	the shell appends filename, which is presumably	a his-
	       tory list saved by the -S option	or the savehist	mechanism,  to
	       the  history list.  -M is like -L, but the contents of filename
	       are merged into the history list	and sorted by  timestamp.   In
	       either  case,  histfile	is  used  if filename is not given and
	       ~/.history is used if histfile is unset.	 `history -L'  is  ex-
	       actly  like 'source -h' except that it does not require a file-
	       name.

	       Note that login shells do the equivalent	 of  `history  -L'  on
	       startup	and,  if savehist is set, `history -S' before exiting.
	       Because only ~/.tcshrc is normally sourced  before  ~/.history,
	       histfile	should be set in ~/.tcshrc rather than ~/.login.

	       If  histlit  is	set, the first and second forms	print and save
	       the literal (unexpanded)	form of	the history list.

	       The last	form clears the	history	list.

       hup [command] (+)
	       With command, runs command such that it will exit on  a	hangup
	       signal  and  arranges  for the shell to send it a hangup	signal
	       when the	shell exits.  Note that	commands may set their own re-
	       sponse  to  hangups,  overriding	hup.  Without an argument (al-
	       lowed in	only a shell script), causes the shell to  exit	 on  a
	       hangup  for  the	remainder of the script.  See also Signal han-
	       dling and the nohup builtin command.

       if (expr) command
	       If expr (an expression, as described under Expressions)	evalu-
	       ates  true, then	command	is executed.  Variable substitution on
	       command happens early, at the same time it does for the rest of
	       the  if	command.   command  must  be  a	simple command,	not an
	       alias, a	pipeline, a command list or  a	parenthesized  command
	       list,  but it may have arguments.  Input/output redirection oc-
	       curs even if expr is false and command is  thus	not  executed;
	       this is a bug.

       if (expr) then
       ...
       else if (expr2) then
       ...
       else
       ...
       endif   If  the	specified  expr	is true	then the commands to the first
	       else are	executed; otherwise if expr2 is	true then the commands
	       to  the	second	else are executed, etc.	 Any number of else-if
	       pairs are possible; only	one endif is needed.  The else part is
	       likewise	 optional.   (The  words else and endif	must appear at
	       the beginning of	input lines; the if must appear	alone  on  its
	       input line or after an else.)

       inlib shared-library ...	(+)
	       Adds  each shared-library to the	current	environment.  There is
	       no way to remove	a shared library.  (Domain/OS only)

       jobs [-l]
	       Lists the active	jobs.  With -l,	lists process IDs in  addition
	       to  the normal information.  On TCF systems, prints the site on
	       which each job is executing.

       kill [-s	signal]	%job|pid ...
       kill -l The first and second forms sends	the specified signal  (or,  if
	       none  is	 given,	 the TERM (terminate) signal) to the specified
	       jobs or processes.  job may be a	number,	a string, `', `%', `+'
	       or  `-'	as  described under Jobs.  Signals are either given by
	       number or by name (as given in /usr/include/signal.h,  stripped
	       of  the	prefix	`SIG').	  There	is no default job; saying just
	       `kill' does not send a signal to	the current job.  If the  sig-
	       nal  being  sent	 is TERM (terminate) or	HUP (hangup), then the
	       job or process is sent a	CONT (continue)	signal as  well.   The
	       third form lists	the signal names.

       limit [-h] [resource [maximum-use]]
	       Limits  the consumption by the current process and each process
	       it creates to not individually exceed maximum-use on the	speci-
	       fied  resource.	 If  no	maximum-use is given, then the current
	       limit is	printed; if no resource	is given, then all limitations
	       are  given.   If	the -h flag is given, the hard limits are used
	       instead of the current limits.  The hard	limits impose a	 ceil-
	       ing  on	the values of the current limits.  Only	the super-user
	       may raise the hard limits, but a	user may lower	or  raise  the
	       current limits within the legal range.

	       Controllable  resources	currently include (if supported	by the
	       OS):

	       cputime
		      the maximum number of cpu-seconds	to  be	used  by  each
		      process

	       filesize
		      the largest single file which can	be created

	       datasize
		      the  maximum growth of the data+stack region via sbrk(2)
		      beyond the end of	the program text

	       stacksize
		      the maximum size of the automatically-extended stack re-
		      gion

	       coredumpsize
		      the size of the largest core dump	that will be created

	       memoryuse
		      the maximum amount of physical memory a process may have
		      allocated	to it at a given time

	       heapsize
		      the maximum amount of memory a process may allocate  per
		      brk() system call

	       descriptors or openfiles
		      the maximum number of open files for this	process

	       concurrency
		      the maximum number of threads for	this process

	       memorylocked
		      the  maximum  size  which	a process may lock into	memory
		      using mlock(2)

	       maxproc
		      the maximum number of simultaneous  processes  for  this
		      user id

	       sbsize the maximum size of socket buffer	usage for this user

	       swapsize
		      the  maximum  amount  of swap space reserved or used for
		      this user

	       maximum-use may be given	as a (floating point or	integer)  num-
	       ber  followed  by  a  scale  factor.  For all limits other than
	       cputime the default scale is `k'	or `kilobytes' (1024 bytes); a
	       scale  factor  of  `m'  or  `megabytes'	may also be used.  For
	       cputime the default scaling is `seconds', while `m' for minutes
	       or  `h' for hours, or a time of the form	`mm:ss'	giving minutes
	       and seconds may be used.

	       For both	resource names and scale factors, unambiguous prefixes
	       of the names suffice.

       log (+) Prints  the watch shell variable	and reports on each user indi-
	       cated in	watch who is logged in,	regardless of when  they  last
	       logged in.  See also watchlog.

       login   Terminates  a  login  shell,  replacing	it with	an instance of
	       /bin/login. This	is one way to log off, included	 for  compati-
	       bility with sh(1).

       logout  Terminates  a  login  shell.  Especially	useful if ignoreeof is
	       set.

       ls-F [-switch ...] [file	...] (+)
	       Lists files like	`ls -F', but much faster.  It identifies  each
	       type of special file in the listing with	a special character:

	       /   Directory
	       *   Executable
	       #   Block device
	       %   Character device
	       |   Named pipe (systems with named pipes	only)
	       =   Socket (systems with	sockets	only)
	       @   Symbolic link (systems with symbolic	links only)
	       +   Hidden  directory  (AIX  only)  or context dependent	(HP/UX
		   only)
	       :   Network special (HP/UX only)

	       If the listlinks	shell variable	is  set,  symbolic  links  are
	       identified  in  more detail (on only systems that have them, of
	       course):

	       @   Symbolic link to a non-directory
	       >   Symbolic link to a directory
	       &   Symbolic link to nowhere

	       listlinks also slows down ls-F and  causes  partitions  holding
	       files pointed to	by symbolic links to be	mounted.

	       If  the	listflags shell	variable is set	to `x',	`a' or `A', or
	       any combination thereof (e.g., `xA'), they are used as flags to
	       ls-F, making it act like	`ls -xF', `ls -Fa', `ls	-FA' or	a com-
	       bination	(e.g., `ls -FxA').  On machines	where `ls -C'  is  not
	       the default, ls-F acts like `ls -CF', unless listflags contains
	       an `x', in which	case it	acts like `ls -xF'.  ls-F  passes  its
	       arguments  to  ls(1)  if	it is given any	switches, so `alias ls
	       ls-F' generally does the	right thing.

	       The ls-F	builtin	can list files using different colors  depend-
	       ing  on the filetype or extension.  See the color tcsh variable
	       and the LS_COLORS environment variable.

       migrate [-site] pid|%jobid ... (+)
       migrate -site (+)
	       The first form migrates the process or job to the  site	speci-
	       fied  or	 the  default site determined by the system path.  The
	       second form is equivalent to `migrate -site  $$':  it  migrates
	       the current process to the specified site.  Migrating the shell
	       itself can cause	unexpected behavior, because  the  shell  does
	       not like	to lose	its tty.  (TCF only)

       newgrp [-] group	(+)
	       Equivalent  to `exec newgrp'; see newgrp(1).  Available only if
	       the shell was so	compiled; see the version shell	variable.

       nice [+number] [command]
	       Sets the	scheduling priority for	the shell to number, or, with-
	       out  number, to 4.  With	command, runs command at the appropri-
	       ate priority.  The greater the number, the less cpu the process
	       gets.   The  super-user	may specify negative priority by using
	       `nice -number ...'.  Command is always executed in a sub-shell,
	       and the restrictions placed on commands in simple if statements
	       apply.

       nohup [command]
	       With command, runs command such that it will ignore hangup sig-
	       nals.   Note  that  commands  may  set  their  own  response to
	       hangups,	overriding nohup.  Without  an	argument  (allowed  in
	       only  a	shell  script),	causes the shell to ignore hangups for
	       the remainder of	the script.  See also Signal handling and  the
	       hup builtin command.

       notify [%job ...]
	       Causes  the  shell  to  notify the user asynchronously when the
	       status of any of	the specified jobs (or,	without	%job, the cur-
	       rent  job) changes, instead of waiting until the	next prompt as
	       is usual.  job may be a number, a string, `', `%', `+'  or  `-'
	       as described under Jobs.	 See also the notify shell variable.

       onintr [-|label]
	       Controls	 the action of the shell on interrupts.	 Without argu-
	       ments, restores the default action of the shell on  interrupts,
	       which  is to terminate shell scripts or to return to the	termi-
	       nal command input level.	 With `-', causes all interrupts to be
	       ignored.	  With	label, causes the shell	to execute a `goto la-
	       bel' when an interrupt is received or a	child  process	termi-
	       nates because it	was interrupted.

	       onintr  is ignored if the shell is running detached and in sys-
	       tem startup files (see FILES), where  interrupts	 are  disabled
	       anyway.

       popd [-p] [-l] [-n|-v] [+n]
	       Without	arguments, pops	the directory stack and	returns	to the
	       new top directory.  With	a number `+n', discards	the n'th entry
	       in the stack.

	       Finally,	 all  forms  of	 popd print the	final directory	stack,
	       just like dirs.	The pushdsilent	shell variable can be  set  to
	       prevent	this and the -p	flag can be given to override pushdsi-
	       lent.  The -l, -n and -v	flags have the same effect on popd  as
	       on dirs.	 (+)

       printenv	[name] (+)
	       Prints  the  names  and values of all environment variables or,
	       with name, the value of the environment variable	name.

       pushd [-p] [-l] [-n|-v] [name|+n]
	       Without arguments, exchanges the	top two	elements of the	direc-
	       tory  stack.   If  pushdtohome  is set, pushd without arguments
	       does `pushd ~', like cd.	 (+) With  name,  pushes  the  current
	       working directory onto the directory stack and changes to name.
	       If name is `-' it is interpreted	as the previous	working	direc-
	       tory (see Filename substitution).  (+) If dunique is set, pushd
	       removes any instances of	name from the stack before pushing  it
	       onto  the  stack.  (+) With a number `+n', rotates the nth ele-
	       ment of the directory stack around to be	the  top  element  and
	       changes	to  it.	  If  dextract is set, however,	`pushd +n' ex-
	       tracts the nth directory, pushes	it onto	the top	of  the	 stack
	       and changes to it.  (+)

	       Finally,	 all  forms  of	pushd print the	final directory	stack,
	       just like dirs.	The pushdsilent	shell variable can be  set  to
	       prevent	this and the -p	flag can be given to override pushdsi-
	       lent.  The -l, -n and -v	flags have the same effect on pushd as
	       on dirs.	 (+)

       rehash  Causes  the internal hash table of the contents of the directo-
	       ries in the path	variable to be recomputed.  This is needed  if
	       new  commands  are  added  to directories in path while you are
	       logged in.  This	should be necessary only if you	 add  commands
	       to  one	of  your  own  directories, or if a systems programmer
	       changes the contents of one of the  system  directories.	  Also
	       flushes the cache of home directories built by tilde expansion.

       repeat count command
	       The  specified  command,	 which is subject to the same restric-
	       tions as	the command in the one line if statement above,	is ex-
	       ecuted  count times.  I/O redirections occur exactly once, even
	       if count	is 0.

       rootnode	//nodename (+)
	       Changes the rootnode to //nodename, so that `/' will be	inter-
	       preted as `//nodename'.	(Domain/OS only)

       sched (+)
       sched [+]hh:mm command (+)
       sched -n	(+)
	       The  first  form	 prints	 the  scheduled-event list.  The sched
	       shell variable may be set to define the	format	in  which  the
	       scheduled-event	list is	printed.  The second form adds command
	       to the scheduled-event list.  For example,

		   > sched 11:00 echo It\'s eleven o\'clock.

	       causes the shell	to echo	`It's eleven o'clock.' at 11 AM.   The
	       time may	be in 12-hour AM/PM format

		   > sched 5pm set prompt='[%h]	It\'s after 5; go home:	>'

	       or may be relative to the current time:

		   > sched +2:15 /usr/lib/uucp/uucico -r1 -sother

	       A  relative  time  specification	may not	use AM/PM format.  The
	       third form removes item n from the event	list:

		   > sched
			1  Wed Apr  4 15:42  /usr/lib/uucp/uucico -r1 -sother
			2  Wed Apr  4 17:00  set prompt=[%h] It's after	5;  go
		   home: >
		   > sched -2
		   > sched
			1  Wed Apr  4 15:42  /usr/lib/uucp/uucico -r1 -sother

	       A  command  in the scheduled-event list is executed just	before
	       the first prompt	is printed after the time when the command  is
	       scheduled.  It is possible to miss the exact time when the com-
	       mand is to be run, but an overdue command will execute  at  the
	       next  prompt.   A  command  which  comes	due while the shell is
	       waiting for user	input is executed immediately.	However,  nor-
	       mal  operation of an already-running command will not be	inter-
	       rupted so that a	scheduled-event	list element may be run.

	       This mechanism is similar to, but not the same  as,  the	 at(1)
	       command	on  some Unix systems.	Its major disadvantage is that
	       it may not run a	command	at exactly the	specified  time.   Its
	       major  advantage	 is  that because sched	runs directly from the
	       shell, it has access to shell variables and  other  structures.
	       This  provides  a mechanism for changing	one's working environ-
	       ment based on the time of day.

       set
       set name	...
       set name=word ...
       set [-r]	[-f|-l]	name=(wordlist)	... (+)
       set name[index]=word ...
       set -r (+)
       set -r name ... (+)
       set -r name=word	... (+)
	       The first form of the command prints the	 value	of  all	 shell
	       variables.   Variables  which  contain  more than a single word
	       print as	a parenthesized	word list.  The	second form sets  name
	       to  the	null  string.	The third form sets name to the	single
	       word.  The fourth form sets  name  to  the  list	 of  words  in
	       wordlist.   In  all cases the value is command and filename ex-
	       panded.	If -r is specified, the	value is set read-only.	 If -f
	       or -l are specified, set	only unique words keeping their	order.
	       -f prefers the first occurrence of a word,  and	-l  the	 last.
	       The  fifth  form	 sets  the index'th component of name to word;
	       this component must already exist.  The sixth form  lists  only
	       the  names of all shell variables that are read-only.  The sev-
	       enth form makes name read-only, whether or not it has a	value.
	       The  second form	sets name to the null string.  The eighth form
	       is the same as the third	form, but make name read-only  at  the
	       same time.

	       These  arguments	 can  be repeated to set and/or	make read-only
	       multiple	variables in a single  set  command.   Note,  however,
	       that  variable  expansion  happens for all arguments before any
	       setting occurs.	Note also that `=' can	be  adjacent  to  both
	       name  and word or separated from	both by	whitespace, but	cannot
	       be adjacent to only one or  the	other.	 See  also  the	 unset
	       builtin command.

       setenv [name [value]]
	       Without	arguments, prints the names and	values of all environ-
	       ment variables.	Given name, sets the environment variable name
	       to value	or, without value, to the null string.

       setpath path (+)
	       Equivalent to setpath(1).  (Mach	only)

       setspath	LOCAL|site|cpu ... (+)
	       Sets the	system execution path.	(TCF only)

       settc cap value (+)
	       Tells the shell to believe that the terminal capability cap (as
	       defined in termcap(5)) has the value value.  No sanity checking
	       is  done.   Concept terminal users may have to `settc xn	no' to
	       get proper wrapping at the rightmost column.

       setty [-d|-q|-x]	[-a] [[+|-]mode] (+)
	       Controls	which tty modes	(see Terminal  management)  the	 shell
	       does  not  allow	to change.  -d,	-q or -x tells setty to	act on
	       the `edit', `quote' or `execute'	set of tty modes respectively;
	       without -d, -q or -x, `execute' is used.

	       Without	other  arguments,  setty lists the modes in the	chosen
	       set which are fixed on (`+mode')	or off (`-mode').  The	avail-
	       able  modes,  and thus the display, vary	from system to system.
	       With -a,	lists all tty modes in the chosen set whether  or  not
	       they  are  fixed.   With	+mode, -mode or	mode, fixes mode on or
	       off or removes control from mode	in the chosen set.  For	 exam-
	       ple, `setty +echok echoe' fixes `echok' mode on and allows com-
	       mands to	turn `echoe' mode on or	off, both when	the  shell  is
	       executing commands.

       setxvers	[string] (+)
	       Set the experimental version prefix to string, or removes it if
	       string is omitted.  (TCF	only)

       shift [variable]
	       Without arguments, discards argv[1] and shifts the  members  of
	       argv  to	the left.  It is an error for argv not to be set or to
	       have less than one word as value.  With variable, performs  the
	       same function on	variable.

       source [-h] name	[args ...]
	       The  shell reads	and executes commands from name.  The commands
	       are not placed on the history list.  If	any  args  are	given,
	       they are	placed in argv.	 (+) source commands may be nested; if
	       they are	nested too deeply the shell may	run out	 of  file  de-
	       scriptors.   An	error  in a source at any level	terminates all
	       nested source commands.	With -h, commands are  placed  on  the
	       history list instead of being executed, much like `history -L'.

       stop %job|pid ...
	       Stops  the  specified  jobs or processes	which are executing in
	       the background.	job may	be a number, a string, `', `%',	`+' or
	       `-'  as	described under	Jobs.  There is	no default job;	saying
	       just `stop' does	not stop the current job.

       suspend Causes the shell	to stop	in its tracks, much as if it had  been
	       sent  a	stop  signal with ^Z.  This is most often used to stop
	       shells started by su(1).

       switch (string)
       case str1:
	   ...
	   breaksw
       ...
       default:
	   ...
	   breaksw
       endsw   Each case label is successively matched,	against	the  specified
	       string  which is	first command and filename expanded.  The file
	       metacharacters `*', `?' and `[...]'  may	be used	 in  the  case
	       labels,	which  are  variable  expanded.	 If none of the	labels
	       match before a `default'	label is found,	then the execution be-
	       gins  after the default label.  Each case label and the default
	       label must appear at the	beginning  of  a  line.	  The  command
	       breaksw	causes	execution to continue after the	endsw.	Other-
	       wise control may	fall through case labels and default labels as
	       in  C.	If no label matches and	there is no default, execution
	       continues after the endsw.

       telltc (+)
	       Lists the values	of all terminal	capabilities (see termcap(5)).

       termname	[terminal type]	(+)
	       Tests if	terminal type (or the current value of TERM if no ter-
	       minal  type  is	given) has an entry in the hosts termcap(5) or
	       terminfo(5) database. Prints the	terminal type  to  stdout  and
	       returns 0 if an entry is	present	otherwise returns 1.

       time [command]
	       Executes	command	(which must be a simple	command, not an	alias,
	       a pipeline, a command list or a parenthesized command list) and
	       prints a	time summary as	described under	the time variable.  If
	       necessary, an extra shell is created to print the time  statis-
	       tic when	the command completes.	Without	command, prints	a time
	       summary for the current shell and its children.

       umask [value]
	       Sets the	file creation mask to value, which is given in	octal.
	       Common  values  for  the	mask are 002, giving all access	to the
	       group and read and execute access to others,  and  022,	giving
	       read  and  execute  access  to  the  group and others.  Without
	       value, prints the current file creation mask.

       unalias pattern
	       Removes all aliases whose names	match  pattern.	  `unalias  *'
	       thus removes all	aliases.  It is	not an error for nothing to be
	       unaliased.

       uncomplete pattern (+)
	       Removes all completions whose names match pattern.  `uncomplete
	       *'  thus	removes	all completions.  It is	not an error for noth-
	       ing to be uncompleted.

       unhash  Disables	use of the internal hash table to  speed  location  of
	       executed	programs.

       universe	universe (+)
	       Sets the	universe to universe.  (Masscomp/RTU only)

       unlimit [-hf] [resource]
	       Removes the limitation on resource or, if no resource is	speci-
	       fied, all resource limitations.	 With  -h,  the	 corresponding
	       hard  limits  are  removed.   Only  the super-user may do this.
	       Note that unlimit may not exit successful, since	 most  systems
	       do  not	allow descriptors to be	unlimited.  With -f errors are
	       ignored.

       unset pattern
	       Removes all variables whose names match	pattern,  unless  they
	       are  read-only.	 `unset	 *'  thus removes all variables	unless
	       they are	read-only; this	is a bad idea.	It is not an error for
	       nothing to be unset.

       unsetenv	pattern
	       Removes	all  environment  variables whose names	match pattern.
	       `unsetenv *' thus removes all environment variables; this is  a
	       bad idea.  It is	not an error for nothing to be unsetenved.

       ver [systype [command]] (+)
	       Without	arguments, prints SYSTYPE.  With systype, sets SYSTYPE
	       to systype.  With systype and command, executes	command	 under
	       systype.	  systype  may	be  `bsd4.3'  or `sys5.3'.  (Domain/OS
	       only)

       wait    The shell waits for all background jobs.	 If the	shell  is  in-
	       teractive,  an  interrupt  will	disrupt	the wait and cause the
	       shell to	print the names	and job	 numbers  of  all  outstanding
	       jobs.

       warp universe (+)
	       Sets the	universe to universe.  (Convex/OS only)

       watchlog	(+)
	       An  alternate  name for the log builtin command (q.v.).	Avail-
	       able only if the	shell was so compiled; see the	version	 shell
	       variable.

       where command (+)
	       Reports	all  known  instances  of  command, including aliases,
	       builtins	and executables	in path.

       which command (+)
	       Displays	the command that will be executed by the  shell	 after
	       substitutions,  path  searching,	 etc.	The builtin command is
	       just like which(1), but it correctly reports tcsh  aliases  and
	       builtins	 and  is  10 to	100 times faster.  See also the	which-
	       command editor command.

       while (expr)
       ...
       end     Executes	the commands between the while and  the	 matching  end
	       while  expr  (an	 expression,  as  described under Expressions)
	       evaluates non-zero.  while and end must appear alone  on	 their
	       input  lines.   break  and continue may be used to terminate or
	       continue	the loop prematurely.  If the input is a terminal, the
	       user  is	prompted the first time	through	the loop as with fore-
	       ach.

   Special aliases (+)
       If set, each of these aliases executes automatically at	the  indicated
       time.  They are all initially undefined.

       beepcmd Runs when the shell wants to ring the terminal bell.

       cwdcmd  Runs  after every change	of working directory.  For example, if
	       the user	is working on an X window system using xterm(1)	and  a
	       re-parenting  window  manager  that supports title bars such as
	       twm(1) and does

		   > alias cwdcmd  'echo -n "^[]2;${HOST}:$cwd ^G"'

	       then the	shell will change the title of the running xterm(1) to
	       be  the name of the host, a colon, and the full current working
	       directory.  A fancier way to do that is

		   >	      alias	     cwdcmd	     'echo	    -n
		   "^[]2;${HOST}:$cwd^G^[]1;${HOST}^G"'

	       This  will  put the hostname and	working	directory on the title
	       bar but only the	hostname in the	icon manager menu.

	       Note that putting a cd, pushd or	popd in	cwdcmd	may  cause  an
	       infinite	loop.  It is the author's opinion that anyone doing so
	       will get	what they deserve.

       jobcmd  Runs before each	command	gets executed,	or  when  the  command
	       changes	state.	 This  is  similar to postcmd, but it does not
	       print builtins.

		   > alias jobcmd  'echo -n "^[]2\;\!#:q^G"'

	       then executing vi foo.c will put	 the  command  string  in  the
	       xterm title bar.

       helpcommand
	       Invoked	by  the	run-help editor	command.  The command name for
	       which help is sought is passed as sole argument.	 For  example,
	       if one does

		   > alias helpcommand '\!:1 --help'

	       then  the  help	display	of the command itself will be invoked,
	       using the GNU help calling convention.  Currently there	is  no
	       easy  way to account for	various	calling	conventions (e.g., the
	       customary Unix `-h'), except by using a table of	many commands.

       periodic
	       Runs every tperiod minutes.  This provides a  convenient	 means
	       for checking on common but infrequent changes such as new mail.
	       For example, if one does

		   > set tperiod = 30
		   > alias periodic checknews

	       then the	checknews(1) program runs every	30 minutes.  If	 peri-
	       odic  is	set but	tperiod	is unset or set	to 0, periodic behaves
	       like precmd.

       precmd  Runs just before	each prompt is printed.	 For example,  if  one
	       does

		   > alias precmd date

	       then  date(1)  runs just	before the shell prompts for each com-
	       mand.  There are	no limits on what precmd can be	set to do, but
	       discretion should be used.

       postcmd Runs before each	command	gets executed.

		   > alias postcmd  'echo -n "^[]2\;\!#:q^G"'

	       then  executing	vi  foo.c  will	 put the command string	in the
	       xterm title bar.

       shell   Specifies the interpreter for executable	scripts	which  do  not
	       themselves  specify an interpreter.  The	first word should be a
	       full path name to the desired interpreter (e.g.,	`/bin/csh'  or
	       `/usr/local/bin/tcsh').

   Special shell variables
       The  variables  described  in  this section have	special	meaning	to the
       shell.

       The  shell  sets	 addsuffix,  argv,  autologout,	 csubstnonl,  command,
       echo_style,  edit,  gid,	 group,	 home,	loginsh,  oid,	path,  prompt,
       prompt2,	prompt3, shell,	shlvl, tcsh, term, tty,	uid, user and  version
       at  startup;  they do not change	thereafter unless changed by the user.
       The shell updates cwd, dirstack,	owd and	 status	 when  necessary,  and
       sets logout on logout.

       The shell synchronizes group, home, path, shlvl,	term and user with the
       environment variables of	the same names:	whenever the environment vari-
       able  changes  the  shell  changes  the corresponding shell variable to
       match (unless the shell variable	is read-only) and  vice	 versa.	  Note
       that  although  cwd  and	PWD have identical meanings, they are not syn-
       chronized in this manner, and that the  shell  automatically  intercon-
       verts the different formats of path and PATH.

       addsuffix (+)
	       If  set,	filename completion adds `/' to	the end	of directories
	       and a space to the end of normal	files when  they  are  matched
	       exactly.	 Set by	default.

       afsuser (+)
	       If set, autologout's autolock feature uses its value instead of
	       the local username for kerberos authentication.

       ampm (+)
	       If set, all times are shown in 12-hour AM/PM format.

       argv    The arguments to	the shell.  Positional	parameters  are	 taken
	       from  argv,  i.e., `$1' is replaced by `$argv[1]', etc.	Set by
	       default,	but usually empty in interactive shells.

       autocorrect (+)
	       If set, the spell-word editor command is	invoked	 automatically
	       before each completion attempt.

       autoexpand (+)
	       If  set,	the expand-history editor command is invoked automati-
	       cally before each completion attempt. If	this is	set  to	 only-
	       history,	 then  only history will be expanded and a second com-
	       pletion will expand filenames.

       autolist	(+)
	       If set, possibilities are listed	after an ambiguous completion.
	       If  set	to  `ambiguous', possibilities are listed only when no
	       new characters are added	by completion.

       autologout (+)
	       The first word is the number of minutes	of  inactivity	before
	       automatic  logout.   The	 optional second word is the number of
	       minutes of inactivity before automatic locking.	When the shell
	       automatically logs out, it prints `auto-logout',	sets the vari-
	       able logout to `automatic' and exits.  When the shell automati-
	       cally locks, the	user is	required to enter his password to con-
	       tinue working.  Five incorrect attempts result in automatic lo-
	       gout.   Set  to `60' (automatic logout after 60 minutes,	and no
	       locking)	by default in login and	superuser shells, but  not  if
	       the shell thinks	it is running under a window system (i.e., the
	       DISPLAY environment variable is set), the tty is	 a  pseudo-tty
	       (pty)  or  the shell was	not so compiled	(see the version shell
	       variable).  See also the	afsuser	and logout shell variables.

       backslash_quote (+)
	       If set, backslashes (`\') always	quote `\', `'',	and `"'.  This
	       may  make complex quoting tasks easier, but it can cause	syntax
	       errors in csh(1)	scripts.

       catalog The file	name  of  the  message	catalog.   If  set,  tcsh  use
	       `tcsh.${catalog}'  as  a	 message  catalog  instead  of default
	       `tcsh'.

       cdpath  A list of directories in	which cd should	search for subdirecto-
	       ries if they aren't found in the	current	directory.

       color   If  set,	 it  enables color display for the builtin ls-F	and it
	       passes --color=auto to ls.  Alternatively, it  can  be  set  to
	       only ls-F or only ls to enable color to only one	command.  Set-
	       ting it to nothing is equivalent	to setting it to (ls-F ls).

       colorcat
	       If set, it enables color	escape sequence	for NLS	message	files.
	       And display colorful NLS	messages.

       command (+)
	       If  set,	 the command which was passed to the shell with	the -c
	       flag (q.v.).

       compat_expr (+)
	       If set, the shell will evaluate expressions right to left, like
	       the original csh.

       complete	(+)
	       If  set to `enhance', completion	1) ignores case	and 2) consid-
	       ers periods, hyphens and	underscores (`.', `-' and `_')	to  be
	       word  separators	 and hyphens and underscores to	be equivalent.
	       If set to `igncase', the	completion becomes case	insensitive.

       continue	(+)
	       If set to a list	of  commands,  the  shell  will	 continue  the
	       listed commands,	instead	of starting a new one.

       continue_args (+)
	       Same as continue, but the shell will execute:

		   echo	`pwd` $argv > ~/.<cmd>_pause; %<cmd>

       correct (+)
	       If set to `cmd',	commands are automatically spelling-corrected.
	       If set to `complete', commands are automatically	completed.  If
	       set to `all', the entire	command	line is	corrected.

       csubstnonl (+)
	       If  set,	 newlines and carriage returns in command substitution
	       are replaced by spaces.	Set by default.

       cwd     The full	pathname of  the  current  directory.	See  also  the
	       dirstack	and owd	shell variables.

       dextract	(+)
	       If  set,	 `pushd	+n' extracts the nth directory from the	direc-
	       tory stack rather than rotating it to the top.

       dirsfile	(+)
	       The default location in which `dirs -S' and `dirs -L' look  for
	       a  history  file.   If unset, ~/.cshdirs	is used.  Because only
	       ~/.tcshrc  is  normally	sourced	 before	 ~/.cshdirs,  dirsfile
	       should be set in	~/.tcshrc rather than ~/.login.

       dirstack	(+)
	       An  array  of  all  the	directories  on	 the  directory	stack.
	       `$dirstack[1]' is the current working directory,	`$dirstack[2]'
	       the  first  directory on	the stack, etc.	 Note that the current
	       working directory is `$dirstack[1]' but `=0' in directory stack
	       substitutions,  etc.   One  can change the stack	arbitrarily by
	       setting dirstack, but the first element	(the  current  working
	       directory)  is  always correct.	See also the cwd and owd shell
	       variables.

       dspmbyte	(+)
	       Has an affect iff 'dspm'	is listed as part of the version shell
	       variable.  If set to `euc', it enables display and editing EUC-
	       kanji(Japanese) code.  If set to	`sjis',	it enables display and
	       editing Shift-JIS(Japanese) code.  If set to `big5', it enables
	       display and editing Big5(Chinese) code.	If set to  `utf8',  it
	       enables	display	and editing Utf8(Unicode) code.	 If set	to the
	       following format, it enables display and	 editing  of  original
	       multi-byte code format:

		   > set dspmbyte = 0000....(256 bytes)....0000

	       The table requires just 256 bytes.  Each	character of 256 char-
	       acters corresponds (from	left to	 right)	 to  the  ASCII	 codes
	       0x00,  0x01,  ...  0xff.	 Each character	is set to number 0,1,2
	       and 3.  Each number has the following meaning:
		 0 ... not used	for multi-byte characters.
		 1 ... used for	the first byte of a multi-byte character.
		 2 ... used for	the second byte	of a multi-byte	character.
		 3 ... used for	both the first	byte  and  second  byte	 of  a
	       multi-byte character.

		 Example:
	       If  set	to  `001322',  the  first character (means 0x00	of the
	       ASCII code) and second character	(means 0x01 of ASCII code) are
	       set  to	`0'.   Then, it	is not used for	multi-byte characters.
	       The 3rd character (0x02)	is set to '1', indicating that	it  is
	       used  for  the  first  byte of a	multi-byte character.  The 4th
	       character(0x03) is set '3'.  It is used for both	the first byte
	       and the second byte of a	multi-byte character.  The 5th and 6th
	       characters (0x04,0x05) are set to '2', indicating that they are
	       used for	the second byte	of a multi-byte	character.

	       The GNU fileutils version of ls cannot display multi-byte file-
	       names without the -N ( --literal	) option.   If you  are	 using
	       this version, set the second word of dspmbyte to	"ls".  If not,
	       for example, "ls-F -l" cannot display multi-byte	filenames.

		 Note:
	       This variable can only be used if KANJI and DSPMBYTE  has  been
	       defined at compile time.

       dunique (+)
	       If  set,	pushd removes any instances of name from the stack be-
	       fore pushing it onto the	stack.

       echo    If set, each command with its arguments is echoed  just	before
	       it  is executed.	 For non-builtin commands all expansions occur
	       before echoing.	Builtin	commands are echoed before command and
	       filename	 substitution,	because	 these	substitutions are then
	       done selectively.  Set by the -x	command	line option.

       echo_style (+)
	       The style of the	echo builtin.  May be set to

	       bsd     Don't echo a newline if the first argument is `-n'.
	       sysv    Recognize backslashed escape sequences in echo strings.
	       both    Recognize both the `-n' flag and	backslashed escape se-
		       quences;	the default.
	       none    Recognize neither.

	       Set by default to the local system default.  The	BSD and	System
	       V options are described in the echo(1) man pages	on the	appro-
	       priate systems.

       edit (+)
	       If set, the command-line	editor is used.	 Set by	default	in in-
	       teractive shells.

       ellipsis	(+)
	       If set, the `%c'/`%.' and `%C' prompt sequences (see the	prompt
	       shell  variable)	 indicate skipped directories with an ellipsis
	       (`...')	instead	of `/<skipped>'.

       fignore (+)
	       Lists file name suffixes	to be ignored by completion.

       filec   In tcsh,	completion is always used and this variable is ignored
	       by  default. If edit is unset, then the traditional csh comple-
	       tion is used.  If set in	csh, filename completion is used.

       gid (+) The user's real group ID.

       group (+)
	       The user's group	name.

       highlight
	       If set, the incremental search match (in	i-search-back  and  i-
	       search-fwd)  and	the region between the mark and	the cursor are
	       highlighted in reverse video.

	       Highlighting requires more frequent terminal writes, which  in-
	       troduces	 extra	overhead.  If  you care	about terminal perfor-
	       mance, you may want to leave this unset.

       histchars
	       A string	value determining the characters used in History  sub-
	       stitution  (q.v.).  The first character of its value is used as
	       the history substitution	character, replacing the default char-
	       acter  `!'.   The  second  character  of	its value replaces the
	       character `^' in	quick substitutions.

       histdup (+)
	       Controls	handling of duplicate entries in the history list.  If
	       set to `all' only unique	history	events are entered in the his-
	       tory list.  If set to `prev' and	the last history event is  the
	       same  as	 the  current command, then the	current	command	is not
	       entered in the history.	If set to `erase' and the  same	 event
	       is  found  in  the history list,	that old event gets erased and
	       the current one gets inserted.  Note that the `prev' and	 `all'
	       options renumber	history	events so there	are no gaps.

       histfile	(+)
	       The  default  location  in  which `history -S' and `history -L'
	       look for	a history file.	 If unset, ~/.history is used.	 hist-
	       file  is	 useful	 when  sharing the same	home directory between
	       different machines, or when saving separate histories  on  dif-
	       ferent  terminals.   Because only ~/.tcshrc is normally sourced
	       before ~/.history, histfile should be set in  ~/.tcshrc	rather
	       than ~/.login.

       histlit (+)
	       If  set,	builtin	and editor commands and	the savehist mechanism
	       use the literal (unexpanded) form of lines in the history list.
	       See also	the toggle-literal-history editor command.

       history The  first word indicates the number of history events to save.
	       The optional second word	(+) indicates the format in which his-
	       tory  is	 printed;  if  not given, `%h\t%T\t%R\n' is used.  The
	       format sequences	are described below  under  prompt;  note  the
	       variable	meaning	of `%R'.  Set to `100' by default.

       home    Initialized to the home directory of the	invoker.  The filename
	       expansion of `~'	refers to this variable.

       ignoreeof
	       If set to the empty string or `0' and the  input	 device	 is  a
	       terminal,  the  end-of-file  command  (usually generated	by the
	       user by typing `^D' on an empty line) causes the	shell to print
	       `Use  "exit" to leave tcsh.' instead of exiting.	 This prevents
	       the shell from accidentally being  killed.   Historically  this
	       setting	exited	after  26  successive  EOF's to	avoid infinite
	       loops.  If set to a number n, the shell ignores n - 1  consecu-
	       tive  end-of-files  and exits on	the nth.  (+) If unset,	`1' is
	       used, i.e., the shell exits on a	single `^D'.

       implicitcd (+)
	       If set, the shell treats	a directory name typed as a command as
	       though  it  were	a request to change to that directory.	If set
	       to verbose, the change of directory is echoed to	 the  standard
	       output.	 This  behavior	 is inhibited in non-interactive shell
	       scripts,	or for	command	 strings  with	more  than  one	 word.
	       Changing	directory takes	precedence over	executing a like-named
	       command,	but it is done after alias substitutions.   Tilde  and
	       variable	expansions work	as expected.

       inputmode (+)
	       If  set	to  `insert' or	`overwrite', puts the editor into that
	       input mode at the beginning of each line.

       killdup (+)
	       Controls	handling of duplicate entries in the  kill  ring.   If
	       set  to `all' only unique strings are entered in	the kill ring.
	       If set to `prev'	and the	last killed string is the same as  the
	       current	killed	string,	then the current string	is not entered
	       in the ring.  If	set to `erase' and the same string is found in
	       the  kill ring, the old string is erased	and the	current	one is
	       inserted.

       killring	(+)
	       Indicates the number of killed strings to keep in memory.   Set
	       to  `30'	 by  default.	If  unset or set to less than `2', the
	       shell will only keep the	most recently killed string.   Strings
	       are  put	 in  the  killring  by the editor commands that	delete
	       (kill) strings of text, e.g.  backward-delete-word,  kill-line,
	       etc, as well as the copy-region-as-kill command.	 The yank edi-
	       tor command will	yank the most recently killed string into  the
	       command-line,  while yank-pop (see Editor commands) can be used
	       to yank earlier killed strings.

       listflags (+)
	       If set to `x', `a' or `A', or any  combination  thereof	(e.g.,
	       `xA'),  they  are used as flags to ls-F,	making it act like `ls
	       -xF', `ls -Fa', `ls -FA'	or a combination  (e.g.,  `ls  -FxA'):
	       `a'  shows all files (even if they start	with a `.'), `A' shows
	       all files but `.' and `..', and `x'  sorts  across  instead  of
	       down.   If  the	second word of listflags is set, it is used as
	       the path	to `ls(1)'.

       listjobs	(+)
	       If set, all jobs	are listed when	a job is suspended.  If	set to
	       `long', the listing is in long format.

       listlinks (+)
	       If  set,	 the  ls-F  builtin  command shows the type of file to
	       which each symbolic link	points.

       listmax (+)
	       The maximum number of items which the list-choices editor  com-
	       mand will list without asking first.

       listmaxrows (+)
	       The maximum number of rows of items which the list-choices edi-
	       tor command will	list without asking first.

       loginsh (+)
	       Set by the shell	if it is a login shell.	 Setting or  unsetting
	       it within a shell has no	effect.	 See also shlvl.

       logout (+)
	       Set  by	the  shell  to `normal'	before a normal	logout,	`auto-
	       matic' before an	automatic logout, and `hangup'	if  the	 shell
	       was  killed by a	hangup signal (see Signal handling).  See also
	       the autologout shell variable.

       mail    The names of the	files or directories  to  check	 for  incoming
	       mail, separated by whitespace, and optionally preceded by a nu-
	       meric word.  Before each	prompt,	 if  10	 minutes  have	passed
	       since  the last check, the shell	checks each file and says `You
	       have new	mail.' (or, if mail contains multiple files, `You have
	       new  mail  in  name.')  if the filesize is greater than zero in
	       size and	has a modification time	greater	than its access	time.

	       If you are in a login shell, then no mail file is reported  un-
	       less  it	has been modified after	the time the shell has started
	       up, to prevent redundant	notifications.	 Most  login  programs
	       will tell you whether or	not you	have mail when you log in.

	       If  a  file  specified  in  mail	is a directory,	the shell will
	       count each file within that directory as	 a  separate  message,
	       and  will  report  `You	have n mails.' or `You have n mails in
	       name.' as appropriate.  This functionality is provided  primar-
	       ily  for	those systems which store mail in this manner, such as
	       the Andrew Mail System.

	       If the first word of mail is numeric it is taken	as a different
	       mail checking interval, in seconds.

	       Under  very  rare circumstances,	the shell may report `You have
	       mail.' instead of `You have new mail.'

       matchbeep (+)
	       If set to `never', completion never  beeps.   If	 set  to  `no-
	       match',	it  beeps only when there is no	match.	If set to `am-
	       biguous', it beeps when there are multiple matches.  If set  to
	       `notunique',  it	beeps when there is one	exact and other	longer
	       matches.	 If unset, `ambiguous' is used.

       nobeep (+)
	       If set, beeping is completely disabled.	See also visiblebell.

       noclobber
	       If set, restrictions are	placed on output redirection to	insure
	       that  files  are	not accidentally destroyed and that `>>' redi-
	       rections	refer to existing  files,  as  described  in  the  In-
	       put/output section.

       noding  If  set,	 disable  the  printing	 of `DING!' in the prompt time
	       specifiers at the change	of hour.

       noglob  If set, Filename	substitution and Directory stack  substitution
	       (q.v.)  are  inhibited.	 This  is most useful in shell scripts
	       which do	not deal with filenames, or after a list of  filenames
	       has been	obtained and further expansions	are not	desirable.

       nokanji (+)
	       If  set	and  the  shell	 supports Kanji	(see the version shell
	       variable), it is	disabled so that the meta key can be used.

       nonomatch
	       If set, a Filename substitution or Directory stack substitution
	       (q.v.)  which  does  not	 match	any existing files is left un-
	       touched rather than causing an error.  It is still an error for
	       the substitution	to be malformed, e.g., `echo ['	still gives an
	       error.

       nostat (+)
	       A list of directories (or glob-patterns	which  match  directo-
	       ries;  see  Filename substitution) that should not be stat(2)ed
	       during a	completion operation.  This is usually used to exclude
	       directories  which  take	 too much time to stat(2), for example
	       /afs.

       notify  If set, the shell  announces  job  completions  asynchronously.
	       The  default is to present job completions just before printing
	       a prompt.

       oid (+) The user's real organization ID.	 (Domain/OS only)

       owd (+) The old working directory, equivalent to	the `-'	used by	cd and
	       pushd.  See also	the cwd	and dirstack shell variables.

       padhour If set, enable the printing of padding '0' for hours, in	24 and
	       12 hour formats.	 E.G.: 07:45:42	vs. 7:45:42

       path    A list of directories in	which to look for executable commands.
	       A  null	word  specifies	the current directory.	If there is no
	       path variable then only full path names will execute.  path  is
	       set  by the shell at startup from the PATH environment variable
	       or, if PATH does	not exist, to a	system-dependent default some-
	       thing  like  `(/usr/local/bin  /usr/bsd /bin /usr/bin .)'.  The
	       shell may put `.' first or last in path or omit it entirely de-
	       pending on how it was compiled; see the version shell variable.
	       A shell which is	given neither the -c nor the -t	option	hashes
	       the contents of the directories in path after reading ~/.tcshrc
	       and each	time path is reset.  If	one adds a new	command	 to  a
	       directory in path while the shell is active, one	may need to do
	       a rehash	for the	shell to find it.

       printexitvalue (+)
	       If set and an interactive program exits with a non-zero status,
	       the shell prints	`Exit status'.

       prompt  The  string  which  is printed before reading each command from
	       the terminal.  prompt may include any of	the following  format-
	       ting  sequences	(+),  which are	replaced by the	given informa-
	       tion:

	       %/  The current working directory.
	       %~  The current working directory, but with one's  home	direc-
		   tory	 represented  by `~' and other users' home directories
		   represented	by  `~user'  as	 per  Filename	 substitution.
		   `~user'  substitution happens only if the shell has already
		   used	`~user'	in a pathname in the current session.
	       %c[[0]n], %.[[0]n]
		   The trailing	component of the current working directory, or
		   n  trailing	components if a	digit n	is given.  If n	begins
		   with	`0', the number	 of  skipped  components  precede  the
		   trailing  component(s)  in the format `/<skipped>trailing'.
		   If the ellipsis shell variable is set,  skipped  components
		   are	represented  by	 an  ellipsis  so  the	whole  becomes
		   `...trailing'.  `~' substitution is done as in `%~'	above,
		   but	the  `~'  component  is	ignored	when counting trailing
		   components.
	       %C  Like	%c, but	without	`~' substitution.
	       %h, %!, !
		   The current history event number.
	       %M  The full hostname.
	       %m  The hostname	up to the first	`.'.
	       %S (%s)
		   Start (stop)	standout mode.
	       %B (%b)
		   Start (stop)	boldfacing mode.
	       %U (%u)
		   Start (stop)	underline mode.
	       %t, %@
		   The time of day in 12-hour AM/PM format.
	       %T  Like	`%t', but in 24-hour format (but see  the  ampm	 shell
		   variable).
	       %p  The	`precise'  time	 of  day in 12-hour AM/PM format, with
		   seconds.
	       %P  Like	`%p', but in 24-hour format (but see  the  ampm	 shell
		   variable).
	       \c  c is	parsed as in bindkey.
	       ^c  c is	parsed as in bindkey.
	       %%  A single `%'.
	       %n  The user name.
	       %j  The number of jobs.
	       %d  The weekday in `Day'	format.
	       %D  The day in `dd' format.
	       %w  The month in	`Mon' format.
	       %W  The month in	`mm' format.
	       %y  The year in `yy' format.
	       %Y  The year in `yyyy' format.
	       %l  The shell's tty.
	       %L  Clears  from	the end	of the prompt to end of	the display or
		   the end of the line.
	       %$  Expands the shell or	environment variable name  immediately
		   after the `$'.
	       %#  `>'	(or the	first character	of the promptchars shell vari-
		   able) for normal users, `#' (or  the	 second	 character  of
		   promptchars)	for the	superuser.
	       %{string%}
		   Includes string as a	literal	escape sequence.  It should be
		   used	only to	change terminal	attributes and should not move
		   the	cursor	location.  This	cannot be the last sequence in
		   prompt.
	       %?  The return code of the command  executed  just  before  the
		   prompt.
	       %R  In prompt2, the status of the parser.  In prompt3, the cor-
		   rected string.  In history, the history string.

	       `%B', `%S', `%U'	and `%{string%}' are available in only	eight-
	       bit-clean shells; see the version shell variable.

	       The  bold,  standout  and underline sequences are often used to
	       distinguish a superuser shell.  For example,

		   > set prompt	= "%m [%h] %B[%@]%b [%/] you rang? "
		   tut [37] [2:54pm] [/usr/accts/sys] you rang?	_

	       If `%t',	`%@', `%T', `%p', or `%P' is used, and noding  is  not
	       set,  then print	`DING!'	on the change of hour (i.e, `:00' min-
	       utes) instead of	the actual time.

	       Set by default to `%# ' in interactive shells.

       prompt2 (+)
	       The string with which to	prompt in while	and foreach loops  and
	       after  lines  ending  in	`\'.  The same format sequences	may be
	       used as in prompt (q.v.); note the variable  meaning  of	 `%R'.
	       Set by default to `%R? '	in interactive shells.

       prompt3 (+)
	       The  string  with  which	 to  prompt  when confirming automatic
	       spelling	correction.  The same format sequences may be used  as
	       in  prompt  (q.v.);  note the variable meaning of `%R'.	Set by
	       default to `CORRECT>%R (y|n|e|a)? ' in interactive shells.

       promptchars (+)
	       If set (to a two-character string),  the	 `%#'  formatting  se-
	       quence  in the prompt shell variable is replaced	with the first
	       character for normal users and the second character for the su-
	       peruser.

       pushdtohome (+)
	       If set, pushd without arguments does `pushd ~', like cd.

       pushdsilent (+)
	       If set, pushd and popd do not print the directory stack.

       recexact	(+)
	       If set, completion completes on an exact	match even if a	longer
	       match is	possible.

       recognize_only_executables (+)
	       If set, command listing displays	only files in  the  path  that
	       are executable.	Slow.

       rmstar (+)
	       If set, the user	is prompted before `rm *' is executed.

       rprompt (+)
	       The string to print on the right-hand side of the screen	(after
	       the command input) when the prompt is being  displayed  on  the
	       left.   It recognizes the same formatting characters as prompt.
	       It will automatically disappear and reappear as	necessary,  to
	       ensure  that command input isn't	obscured, and will appear only
	       if the prompt, command input, and itself	will fit  together  on
	       the  first  line.   If  edit  isn't  set,  then rprompt will be
	       printed after the prompt	and before the command input.

       savedirs	(+)
	       If set, the shell does `dirs -S'	before exiting.	 If the	 first
	       word  is	set to a number, at most that many directory stack en-
	       tries are saved.

       savehist
	       If set, the shell does `history -S'  before  exiting.   If  the
	       first  word  is	set  to	 a number, at most that	many lines are
	       saved.  (The number must	be less	than or	equal to history.)  If
	       the  second  word is set	to `merge', the	history	list is	merged
	       with the	existing history file  instead	of  replacing  it  (if
	       there  is  one)	and  sorted  by	time stamp and the most	recent
	       events are retained.  (+)

       sched (+)
	       The format in which the sched builtin command prints  scheduled
	       events;	if  not	given, `%h\t%T\t%R\n' is used.	The format se-
	       quences are described above under  prompt;  note	 the  variable
	       meaning of `%R'.

       shell   The  file  in which the shell resides.  This is used in forking
	       shells to interpret files which	have  execute  bits  set,  but
	       which  are  not executable by the system.  (See the description
	       of Builtin and non-builtin command execution.)  Initialized  to
	       the (system-dependent) home of the shell.

       shlvl (+)
	       The  number of nested shells.  Reset to 1 in login shells.  See
	       also loginsh.

       status  The status returned by the last command.	 If it terminated  ab-
	       normally,  then	0200 is	added to the status.  Builtin commands
	       which fail return exit status `1', all other  builtin  commands
	       return status `0'.

       symlinks	(+)
	       Can be set to several different values to control symbolic link
	       (`symlink') resolution:

	       If set to `chase', whenever the current directory changes to  a
	       directory  containing  a	 symbolic  link, it is expanded	to the
	       real name of the	directory to which the link points.  This does
	       not work	for the	user's home directory; this is a bug.

	       If  set to `ignore', the	shell tries to construct a current di-
	       rectory relative	to the current directory before	the  link  was
	       crossed.	  This	means  that  cding through a symbolic link and
	       then `cd	..'ing returns one to the  original  directory.	  This
	       affects only builtin commands and filename completion.

	       If  set	to  `expand', the shell	tries to fix symbolic links by
	       actually	expanding arguments which look like path names.	  This
	       affects	any  command,  not just	builtins.  Unfortunately, this
	       does not	work for hard-to-recognize filenames,  such  as	 those
	       embedded	 in  command  options.	 Expansion may be prevented by
	       quoting.	 While this setting is usually the most	convenient, it
	       is  sometimes  misleading and sometimes confusing when it fails
	       to recognize an argument	which should be	expanded.   A  compro-
	       mise  is	 to use	`ignore' and use the editor command normalize-
	       path (bound by default to ^X-n) when necessary.

	       Some examples are in order.  First, let's set up	some play  di-
	       rectories:

		   > cd	/tmp
		   > mkdir from	from/src to
		   > ln	-s from/src to/dst

	       Here's the behavior with	symlinks unset,

		   > cd	/tmp/to/dst; echo $cwd
		   /tmp/to/dst
		   > cd	..; echo $cwd
		   /tmp/from

	       here's the behavior with	symlinks set to	`chase',

		   > cd	/tmp/to/dst; echo $cwd
		   /tmp/from/src
		   > cd	..; echo $cwd
		   /tmp/from

	       here's the behavior with	symlinks set to	`ignore',

		   > cd	/tmp/to/dst; echo $cwd
		   /tmp/to/dst
		   > cd	..; echo $cwd
		   /tmp/to

	       and here's the behavior with symlinks set to `expand'.

		   > cd	/tmp/to/dst; echo $cwd
		   /tmp/to/dst
		   > cd	..; echo $cwd
		   /tmp/to
		   > cd	/tmp/to/dst; echo $cwd
		   /tmp/to/dst
		   > cd	".."; echo $cwd
		   /tmp/from
		   > /bin/echo ..
		   /tmp/to
		   > /bin/echo ".."
		   ..

	       Note  that  `expand'  expansion 1) works	just like `ignore' for
	       builtins	like cd, 2) is prevented by quoting,  and  3)  happens
	       before filenames	are passed to non-builtin commands.

       tcsh (+)
	       The  version number of the shell	in the format `R.VV.PP', where
	       `R' is the major	release	number,	`VV' the current  version  and
	       `PP' the	patchlevel.

       term    The  terminal type.  Usually set	in ~/.login as described under
	       Startup and shutdown.

       time    If set to a number, then	the time builtin (q.v.)	executes auto-
	       matically  after	 each  command which takes more	than that many
	       CPU seconds.  If	there is a second word,	it is used as a	format
	       string  for  the	output of the time builtin.  (u) The following
	       sequences may be	used in	the format string:

	       %U  The time the	process	spent in user mode in cpu seconds.
	       %S  The time the	process	spent in kernel	mode in	cpu seconds.
	       %E  The elapsed (wall clock) time in seconds.
	       %P  The CPU percentage computed as (%U +	%S) / %E.
	       %W  Number of times the process was swapped.
	       %X  The average amount in (shared) text space used in Kbytes.
	       %D  The average amount in (unshared) data/stack space  used  in
		   Kbytes.
	       %K  The total space used	(%X + %D) in Kbytes.
	       %M  The	maximum	 memory	 the process had in use	at any time in
		   Kbytes.
	       %F  The number of major page faults (page needed	to be  brought
		   from	disk).
	       %R  The number of minor page faults.
	       %I  The number of input operations.
	       %O  The number of output	operations.
	       %r  The number of socket	messages received.
	       %s  The number of socket	messages sent.
	       %k  The number of signals received.
	       %w  The number of voluntary context switches (waits).
	       %c  The number of involuntary context switches.

	       Only  the first four sequences are supported on systems without
	       BSD resource limit functions.  The default time format is  `%Uu
	       %Ss %E %P %X+%Dk	%I+%Oio	%Fpf+%Ww' for systems that support re-
	       source usage reporting and `%Uu %Ss %E %P' for systems that  do
	       not.

	       Under Sequent's DYNIX/ptx, %X, %D, %K, %r and %s	are not	avail-
	       able, but the following additional sequences are:

	       %Y  The number of system	calls performed.
	       %Z  The number of pages which are zero-filled on	demand.
	       %i  The number of times a process's resident set	size  was  in-
		   creased by the kernel.
	       %d  The	number	of times a process's resident set size was de-
		   creased by the kernel.
	       %l  The number of read system calls performed.
	       %m  The number of write system calls performed.
	       %p  The number of reads from raw	disk devices.
	       %q  The number of writes	to raw disk devices.

	       and  the	 default  time	format	is  `%Uu  %Ss  %E  %P  %I+%Oio
	       %Fpf+%Ww'.   Note  that	the  CPU percentage can	be higher than
	       100% on multi-processors.

       tperiod (+)
	       The period, in minutes, between executions of the periodic spe-
	       cial alias.

       tty (+) The name	of the tty, or empty if	not attached to	one.

       uid (+) The user's real user ID.

       user    The user's login	name.

       verbose If  set,	 causes	the words of each command to be	printed, after
	       history substitution (if	any).  Set by the -v command line  op-
	       tion.

       version (+)
	       The  version  ID	stamp.	It contains the	shell's	version	number
	       (see tcsh), origin, release date, vendor, operating system  and
	       machine (see VENDOR, OSTYPE and MACHTYPE) and a comma-separated
	       list of options which were set at compile time.	Options	 which
	       are set by default in the distribution are noted.

	       8b    The shell is eight	bit clean; default
	       7b    The shell is not eight bit	clean
	       wide  The shell is multibyte encoding clean (like UTF-8)
	       nls   The system's NLS is used; default for systems with	NLS
	       lf    Login shells execute /etc/csh.login before	instead	of af-
		     ter /etc/csh.cshrc	and ~/.login before instead  of	 after
		     ~/.tcshrc and ~/.history.
	       dl    `.' is put	last in	path for security; default
	       nd    `.' is omitted from path for security
	       vi    vi-style editing is the default rather than emacs
	       dtr   Login shells drop DTR when	exiting
	       bye   bye  is a synonym for logout and log is an	alternate name
		     for watchlog
	       al    autologout	is enabled; default
	       kan   Kanji is used if appropriate  according  to  locale  set-
		     tings, unless the nokanji shell variable is set
	       sm    The system's malloc(3) is used
	       hb    The `#!<program> <args>' convention is emulated when exe-
		     cuting shell scripts
	       ng    The newgrp	builtin	is available
	       rh    The shell attempts	 to  set  the  REMOTEHOST  environment
		     variable
	       afs   The shell verifies	your password with the kerberos	server
		     if	local authentication fails.  The afsuser  shell	 vari-
		     able  or  the  AFSUSER environment	variable override your
		     local username if set.

	       An administrator	may enter additional strings to	indicate  dif-
	       ferences	in the local version.

       visiblebell (+)
	       If  set,	 a  screen flash is used rather	than the audible bell.
	       See also	nobeep.

       watch (+)
	       A list of user/terminal pairs to	watch for logins and  logouts.
	       If  either  the user is `any' all terminals are watched for the
	       given user and  vice  versa.   Setting  watch  to  `(any	 any)'
	       watches all users and terminals.	 For example,

		   set watch = (george ttyd1 any console $user any)

	       reports activity	of the user `george' on	ttyd1, any user	on the
	       console,	and oneself (or	a trespasser) on any terminal.

	       Logins and logouts are checked every 10 minutes by default, but
	       the  first  word	of watch can be	set to a number	to check every
	       so many minutes.	 For example,

		   set watch = (1 any any)

	       reports any login/logout	once every minute.  For	the impatient,
	       the  log	 builtin  command triggers a watch report at any time.
	       All current logins are reported (as with	the log	builtin)  when
	       watch is	first set.

	       The who shell variable controls the format of watch reports.

       who (+) The  format string for watch messages.  The following sequences
	       are replaced by the given information:

	       %n  The name of the user	who logged in/out.
	       %a  The observed	action,	i.e., `logged  on',  `logged  off'  or
		   `replaced olduser on'.
	       %l  The terminal	(tty) on which the user	logged in/out.
	       %M  The full hostname of	the remote host, or `local' if the lo-
		   gin/logout was from the local host.
	       %m  The hostname	of the remote host up to the first  `.'.   The
		   full	 name is printed if it is an IP	address	or an X	Window
		   System display.

	       %M and %m are available on only systems that store  the	remote
	       hostname	 in  /etc/utmp.	  If unset, `%n	has %a %l from %m.' is
	       used, or	`%n has	%a %l.'	on systems which don't store  the  re-
	       mote hostname.

       wordchars (+)
	       A  list of non-alphanumeric characters to be considered part of
	       a word by the forward-word,  backward-word  etc.,  editor  com-
	       mands.  If unset, `*?_-.[]~=' is	used.

ENVIRONMENT
       AFSUSER (+)
	       Equivalent to the afsuser shell variable.

       COLUMNS The  number  of	columns	in the terminal.  See Terminal manage-
	       ment.

       DISPLAY Used by X Window	System (see X(1)).  If set, the	shell does not
	       set autologout (q.v.).

       EDITOR  The pathname to a default editor.  See also the VISUAL environ-
	       ment variable and the run-fg-editor editor command.

       GROUP (+)
	       Equivalent to the group shell variable.

       HOME    Equivalent to the home shell variable.

       HOST (+)
	       Initialized to the name of the machine on which	the  shell  is
	       running,	as determined by the gethostname(2) system call.

       HOSTTYPE	(+)
	       Initialized  to	the type of machine on which the shell is run-
	       ning, as	determined at compile time.  This variable is obsolete
	       and will	be removed in a	future version.

       HPATH (+)
	       A colon-separated list of directories in	which the run-help ed-
	       itor command looks for command documentation.

       LANG    Gives the preferred character environment.  See Native Language
	       System support.

       LC_CTYPE
	       If  set,	 only ctype character handling is changed.  See	Native
	       Language	System support.

       LINES   The number of lines in the terminal.  See Terminal management.

       LS_COLORS
	       The format of this variable is reminiscent  of  the  termcap(5)
	       file  format; a colon-separated list of expressions of the form
	       "xx=string", where "xx" is a two-character variable name.   The
	       variables with their associated defaults	are:

		   no	0      Normal (non-filename) text
		   fi	0      Regular file
		   di	01;34  Directory
		   ln	01;36  Symbolic	link
		   pi	33     Named pipe (FIFO)
		   so	01;35  Socket
		   do	01;35  Door
		   bd	01;33  Block device
		   cd	01;32  Character device
		   ex	01;32  Executable file
		   mi	(none) Missing file (defaults to fi)
		   or	(none) Orphaned	symbolic link (defaults	to ln)
		   lc	^[[    Left code
		   rc	m      Right code
		   ec	(none) End code	(replaces lc+no+rc)

	       You  need to include only the variables you want	to change from
	       the default.

	       File names can also be colorized	based on  filename  extension.
	       This  is	 specified  in the LS_COLORS variable using the	syntax
	       "*ext=string".  For example, using ISO 6429 codes, to color all
	       C-language  source files	blue you would specify "*.c=34".  This
	       would color all files ending in .c in blue (34) color.

	       Control characters can be written either	in C-style-escaped no-
	       tation,	or in stty-like	^-notation.  The C-style notation adds
	       ^[ for Escape, _	for  a	normal	space  character,  and	?  for
	       Delete.	 In  addition,	the ^[ escape character	can be used to
	       override	the default interpretation of ^[, ^, : and =.

	       Each file will be written as <lc> <color-code> <rc>  <filename>
	       <ec>.   If  the	<ec> code is undefined,	the sequence <lc> <no>
	       <rc> will be used instead.  This	is generally  more  convenient
	       to  use,	 but  less general.  The left, right and end codes are
	       provided	so you don't have to type common parts over  and  over
	       again  and  to  support weird terminals;	you will generally not
	       need to change them at all unless your terminal	does  not  use
	       ISO 6429	color sequences	but a different	system.

	       If your terminal	does use ISO 6429 color	codes, you can compose
	       the type	codes (i.e., all except	the lc,	rc, and	ec codes) from
	       numerical  commands  separated  by semicolons.  The most	common
	       commands	are:

		       0   to restore default color
		       1   for brighter	colors
		       4   for underlined text
		       5   for flashing	text
		       30  for black foreground
		       31  for red foreground
		       32  for green foreground
		       33  for yellow (or brown) foreground
		       34  for blue foreground
		       35  for purple foreground
		       36  for cyan foreground
		       37  for white (or gray) foreground
		       40  for black background
		       41  for red background
		       42  for green background
		       43  for yellow (or brown) background
		       44  for blue background
		       45  for purple background
		       46  for cyan background
		       47  for white (or gray) background

	       Not all commands	will work on all systems or display devices.

	       A few terminal programs do not recognize	the default  end  code
	       properly.   If all text gets colorized after you	do a directory
	       listing,	try changing the no and	fi codes from 0	to the numeri-
	       cal codes for your standard fore- and background	colors.

       MACHTYPE	(+)
	       The  machine  type  (microprocessor class or machine model), as
	       determined at compile time.

       NOREBIND	(+)
	       If set, printable characters are	not  rebound  to  self-insert-
	       command.	 See Native Language System support.

       OSTYPE (+)
	       The operating system, as	determined at compile time.

       PATH    A colon-separated list of directories in	which to look for exe-
	       cutables.  Equivalent to	the path shell variable, but in	a dif-
	       ferent format.

       PWD (+) Equivalent  to  the cwd shell variable, but not synchronized to
	       it; updated only	after an actual	directory change.

       REMOTEHOST (+)
	       The host	from which the user has	logged in remotely, if this is
	       the  case  and  the shell is able to determine it.  Set only if
	       the shell was so	compiled; see the version shell	variable.

       SHLVL (+)
	       Equivalent to the shlvl shell variable.

       SYSTYPE (+)
	       The current system type.	 (Domain/OS only)

       TERM    Equivalent to the term shell variable.

       TERMCAP The terminal capability string.	See Terminal management.

       USER    Equivalent to the user shell variable.

       VENDOR (+)
	       The vendor, as determined at compile time.

       VISUAL  The pathname to a default full-screen editor.  See also the ED-
	       ITOR environment	variable and the run-fg-editor editor command.

FILES
       /etc/csh.cshrc  Read first by every shell.  ConvexOS, Stellix and Intel
		       use /etc/cshrc and  NeXTs  use  /etc/cshrc.std.	 A/UX,
		       AMIX,  Cray  and	IRIX have no equivalent	in csh(1), but
		       read this file in tcsh anyway.  Solaris	2.x  does  not
		       have it either, but tcsh	reads /etc/.cshrc.  (+)
       /etc/csh.login  Read  by	 login shells after /etc/csh.cshrc.  ConvexOS,
		       Stellix and Intel use /etc/login,  NeXTs	 use  /etc/lo-
		       gin.std,	 Solaris  2.x uses /etc/.login and A/UX, AMIX,
		       Cray and	IRIX use /etc/cshrc.
       ~/.tcshrc (+)   Read by every shell after /etc/csh.cshrc	or its equiva-
		       lent.
       ~/.cshrc	       Read  by	every shell, if	~/.tcshrc doesn't exist, after
		       /etc/csh.cshrc or its  equivalent.   This  manual  uses
		       `~/.tcshrc'  to mean `~/.tcshrc or, if ~/.tcshrc	is not
		       found, ~/.cshrc'.
       ~/.history      Read by login shells after  ~/.tcshrc  if  savehist  is
		       set, but	see also histfile.
       ~/.login	       Read  by	 login	shells	after ~/.tcshrc	or ~/.history.
		       The shell may be	compiled to read ~/.login  before  in-
		       stead  of  after	~/.tcshrc and ~/.history; see the ver-
		       sion shell variable.
       ~/.cshdirs (+)  Read by login shells after ~/.login if savedirs is set,
		       but see also dirsfile.
       /etc/csh.logout Read  by	login shells at	logout.	 ConvexOS, Stellix and
		       Intel use /etc/logout and  NeXTs	 use  /etc/logout.std.
		       A/UX, AMIX, Cray	and IRIX have no equivalent in csh(1),
		       but read	this file in tcsh anyway.   Solaris  2.x  does
		       not have	it either, but tcsh reads /etc/.logout.	 (+)
       ~/.logout       Read by login shells at logout after /etc/csh.logout or
		       its equivalent.
       /bin/sh	       Used to interpret shell scripts	not  starting  with  a
		       `#'.
       /tmp/sh*	       Temporary file for `<<'.
       /etc/passwd     Source of home directories for `~name' substitutions.

       The  order  in which startup files are read may differ if the shell was
       so compiled; see	Startup	and shutdown and the version shell variable.

NEW FEATURES (+)
       This manual describes tcsh as a single entity, but  experienced	csh(1)
       users will want to pay special attention	to tcsh's new features.

       A  command-line	editor,	 which	supports  GNU Emacs or vi(1)-style key
       bindings.  See The command-line editor and Editor commands.

       Programmable, interactive word completion and listing.  See  Completion
       and listing and the complete and	uncomplete builtin commands.

       Spelling	correction (q.v.) of filenames,	commands and variables.

       Editor commands (q.v.) which perform other useful functions in the mid-
       dle of typed commands, including	documentation lookup (run-help), quick
       editor  restarting  (run-fg-editor)  and	command	resolution (which-com-
       mand).

       An enhanced history mechanism.  Events in the history  list  are	 time-
       stamped.	  See  also the	history	command	and its	associated shell vari-
       ables, the previously undocumented `#' event specifier  and  new	 modi-
       fiers  under  History substitution, the *-history, history-search-*, i-
       search-*, vi-search-* and toggle-literal-history	 editor	 commands  and
       the histlit shell variable.

       Enhanced	 directory  parsing and	directory stack	handling.  See the cd,
       pushd, popd and dirs commands and their associated shell	variables, the
       description of Directory	stack substitution, the	dirstack, owd and sym-
       links shell variables and the normalize-command and normalize-path edi-
       tor commands.

       Negation	in glob-patterns.  See Filename	substitution.

       New  File  inquiry  operators  (q.v.) and a filetest builtin which uses
       them.

       A variety of Automatic, periodic	 and  timed  events  (q.v.)  including
       scheduled  events, special aliases, automatic logout and	terminal lock-
       ing, command timing and watching	for logins and logouts.

       Support for the Native Language System (see Native Language System sup-
       port),  OS  variant features (see OS variant support and	the echo_style
       shell variable) and system-dependent file locations (see	FILES).

       Extensive terminal-management capabilities.  See	Terminal management.

       New builtin commands including builtins,	hup, ls-F,  newgrp,  printenv,
       which and where (q.v.).

       New  variables  that  make  useful  information easily available	to the
       shell.  See the gid, loginsh, oid, shlvl, tcsh, tty,  uid  and  version
       shell  variables	 and the HOST, REMOTEHOST, VENDOR, OSTYPE and MACHTYPE
       environment variables.

       A new syntax for	including useful information in	the prompt string (see
       prompt).	  and  special	prompts	for loops and spelling correction (see
       prompt2 and prompt3).

       Read-only variables.  See Variable substitution.

BUGS
       When a suspended	command	is restarted, the shell	prints	the  directory
       it  started  in	if this	is different from the current directory.  This
       can be misleading (i.e.,	wrong) as the job may have changed directories
       internally.

       Shell  builtin  functions  are  not stoppable/restartable.  Command se-
       quences of the form `a ;	b ; c' are also	not  handled  gracefully  when
       stopping	is attempted.  If you suspend `b', the shell will then immedi-
       ately execute `c'.  This	is especially noticeable if this expansion re-
       sults  from an alias.  It suffices to place the sequence	of commands in
       ()'s to force it	to a subshell, i.e., `(	a ; b ;	c )'.

       Control over tty	output after processes are started is primitive;  per-
       haps  this  will	inspire	someone	to work	on a good virtual terminal in-
       terface.	 In a virtual terminal interface much more interesting	things
       could be	done with output control.

       Alias substitution is most often	used to	clumsily simulate shell	proce-
       dures; shell procedures should be provided rather than aliases.

       Commands	within loops are not placed  in	 the  history  list.   Control
       structures  should  be  parsed rather than being	recognized as built-in
       commands.  This would allow control commands to be placed anywhere,  to
       be combined with	`|', and to be used with `&' and `;' metasyntax.

       foreach doesn't ignore here documents when looking for its end.

       It should be possible to	use the	`:' modifiers on the output of command
       substitutions.

       The screen update for lines longer than the screen width	is  very  poor
       if the terminal cannot move the cursor up (i.e.,	terminal type `dumb').

       HPATH and NOREBIND don't	need to	be environment variables.

       Glob-patterns  which  do	 not use `?', `*' or `[]' or which use `{}' or
       `~' are not negated correctly.

       The single-command form of if does output redirection even if  the  ex-
       pression	is false and the command is not	executed.

       ls-F includes file identification characters when sorting filenames and
       does not	handle control characters in filenames well.  It cannot	be in-
       terrupted.

       Command substitution supports multiple commands and conditions, but not
       cycles or backward gotos.

       Report bugs at http://bugs.gw.com/, preferably with fixes.  If you want
       to  help	 maintain  and	test tcsh, send	mail to	tcsh-request@mx.gw.com
       with the	text `subscribe	tcsh' on a line	by itself in the body.

THE T IN TCSH
       In 1964,	DEC produced the PDP-6.	 The PDP-10 was	a later	re-implementa-
       tion.   It  was	re-christened  the DECsystem-10	in 1970	or so when DEC
       brought out the second model, the KI10.

       TENEX was created at Bolt, Beranek & Newman (a Cambridge, Massachusetts
       think tank) in 1972 as an experiment in demand-paged virtual memory op-
       erating systems.	 They built a new pager	for the	DEC PDP-10 and created
       the OS to go with it.  It was extremely successful in academia.

       In  1975, DEC brought out a new model of	the PDP-10, the	KL10; they in-
       tended to have only a version of	TENEX, which they  had	licensed  from
       BBN,  for  the new box.	They called their version TOPS-20 (their capi-
       talization is trademarked).  A lot of  TOPS-10  users  (`The  OPerating
       System  for PDP-10') objected; thus DEC found themselves	supporting two
       incompatible systems on the same	hardware--but then there were 6	on the
       PDP-11!

       TENEX,  and  TOPS-20  to	 version 3, had	command	completion via a user-
       code-level subroutine library called ULTCMD.  With version 3, DEC moved
       all  that  capability  and more into the	monitor	(`kernel' for you Unix
       types), accessed	by the COMND% JSYS (`Jump to SYStem' instruction,  the
       supervisor call mechanism [are my IBM roots also	showing?]).

       The creator of tcsh was impressed by this feature and several others of
       TENEX and TOPS-20, and created a	version	of csh which mimicked them.

LIMITATIONS
       The system limits argument lists	to ARG_MAX characters.

       The number of arguments to a command which involves filename  expansion
       is  limited  to	1/6th  the number of characters	allowed	in an argument
       list.

       Command substitutions may substitute no more characters	than  are  al-
       lowed in	an argument list.

       To  detect  looping,  the shell restricts the number of alias substitu-
       tions on	a single line to 20.

SEE ALSO
       csh(1), emacs(1), ls(1),	newgrp(1), sh(1), setpath(1), stty(1),	su(1),
       tset(1),	  vi(1),   x(1),  access(2),  execve(2),  fork(2),  killpg(2),
       pipe(2),	setrlimit(2), sigvec(2), stat(2), umask(2), vfork(2), wait(2),
       malloc(3),  setlocale(3),  tty(4),  a.out(5),  termcap(5),  environ(7),
       termio(7), Introduction to the C	Shell

VERSION
       This manual documents tcsh 6.17.00 (Astron) 2009-07-10.

AUTHORS
       William Joy
	 Original author of csh(1)
       J.E. Kulp, IIASA, Laxenburg, Austria
	 Job control and directory stack features
       Ken Greer, HP Labs, 1981
	 File name completion
       Mike Ellis, Fairchild, 1983
	 Command name recognition/completion
       Paul Placeway, Ohio State CIS Dept., 1983-1993
	 Command line editor, prompt routines, new glob	 syntax	 and  numerous
	 fixes and speedups
       Karl Kleinpaste,	CCI 1983-4
	 Special  aliases,  directory  stack  extraction  stuff,  login/logout
	 watch,	scheduled events, and the idea of the new prompt format
       Rayan Zachariassen, University of Toronto, 1984
	 ls-F and which	builtins and numerous  bug  fixes,  modifications  and
	 speedups
       Chris Kingsley, Caltech
	 Fast storage allocator	routines
       Chris Grevstad, TRW, 1987
	 Incorporated 4.3BSD csh into tcsh
       Christos	S. Zoulas, Cornell U. EE Dept.,	1987-94
	 Ports	 to   HPUX,   SVR2  and	 SVR3,	a  SysV	 version  of  getwd.c,
	 SHORT_STRINGS support and a new version of sh.glob.c
       James J Dempsey,	BBN, and Paul Placeway,	OSU, 1988
	 A/UX port
       Daniel Long, NNSC, 1988
	 wordchars
       Patrick Wolfe, Kuck and Associates, Inc., 1988
	 vi mode cleanup
       David C Lawrence, Rensselaer Polytechnic	Institute, 1989
	 autolist and ambiguous	completion listing
       Alec Wolman, DEC, 1989
	 Newlines in the prompt
       Matt Landau, BBN, 1989
	 ~/.tcshrc
       Ray Moody, Purdue Physics, 1989
	 Magic space bar history expansion
       Mordechai ????, Intel, 1989
	 printprompt() fixes and additions
       Kazuhiro	Honda, Dept. of	Computer Science, Keio University, 1989
	 Automatic spelling correction and prompt3
       Per Hedeland, Ellemtel, Sweden, 1990-
	 Various bugfixes, improvements	and manual updates
       Hans J. Albertsson (Sun Sweden)
	 ampm, settc and telltc
       Michael Bloom
	 Interrupt handling fixes
       Michael Fine, Digital Equipment Corp
	 Extended key support
       Eric Schnoebelen, Convex, 1990
	 Convex	support, lots of csh bug fixes,	save and restore of  directory
	 stack
       Ron Flax, Apple,	1990
	 A/UX 2.0 (re)port
       Dan Oscarsson, LTH Sweden, 1990
	 NLS support and simulated NLS support for non NLS sites, fixes
       Johan Widen, SICS Sweden, 1990
	 shlvl,	Mach support, correct-line, 8-bit printing
       Matt Day, Sanyo Icon, 1990
	 POSIX termio support, SysV limit fixes
       Jaap Vermeulen, Sequent,	1990-91
	 Vi mode fixes,	expand-line, window change fixes, Symmetry port
       Martin Boyer, Institut de recherche d'Hydro-Quebec, 1991
	 autolist  beeping  options, modified the history search to search for
	 the whole string from the beginning of	the line to the	cursor.
       Scott Krotz, Motorola, 1991
	 Minix port
       David Dawes, Sydney U. Australia, Physics Dept.,	1991
	 SVR4 job control fixes
       Jose Sousa, Interactive Systems Corp., 1991
	 Extended vi fixes and vi delete command
       Marc Horowitz, MIT, 1991
	 ANSIfication fixes, new exec hashing code, imake fixes, where
       Bruce Sterling Woodcock,	sterling@netcom.com, 1991-1995
	 ETA and Pyramid port, Makefile	and lint fixes,	ignoreeof=n  addition,
	 and various other portability changes and bug fixes
       Jeff Fink, 1992
	 complete-word-fwd and complete-word-back
       Harry C.	Pulley,	1992
	 Coherent port
       Andy Phillips, Mullard Space Science Lab	U.K., 1992
	 VMS-POSIX port
       Beto Appleton, IBM Corp., 1992
	 Walking  process  group fixes,	csh bug	fixes, POSIX file tests, POSIX
	 SIGHUP
       Scott Bolte, Cray Computer Corp., 1992
	 CSOS port
       Kaveh R.	Ghazi, Rutgers University, 1992
	 Tek, m88k, Titan and Masscomp ports and fixes.	 Added	autoconf  sup-
	 port.
       Mark Linderman, Cornell University, 1992
	 OS/2 port
       Mika Liljeberg, liljeber@kruuna.Helsinki.FI, 1992
	 Linux port
       Tim P. Starrin, NASA Langley Research Center Operations,	1993
	 Read-only variables
       Dave Schweisguth, Yale University, 1993-4
	 New man page and tcsh.man2html
       Larry Schwimmer,	Stanford University, 1993
	 AFS and HESIOD	patches
       Luke Mewburn, RMIT University, 1994-6
	 Enhanced directory printing in	prompt,	added ellipsis and rprompt.
       Edward Hutchins,	Silicon	Graphics Inc., 1996
	 Added implicit	cd.
       Martin Kraemer, 1997
	 Ported	to Siemens Nixdorf EBCDIC machine
       Amol Deshpande, Microsoft, 1997
	 Ported	 to  WIN32  (Windows/95	and Windows/NT); wrote all the missing
	 library and message catalog code to interface to Windows.
       Taga Nayuta, 1998
	 Color ls additions.

THANKS TO
       Bryan Dunlap, Clayton Elwell, Karl Kleinpaste, Bob Manson, Steve	Romig,
       Diana  Smetters,	Bob Sutterfield, Mark Verber, Elizabeth	Zwicky and all
       the other people	at Ohio	State for suggestions and encouragement

       All the people on the net, for putting up with, reporting bugs in,  and
       suggesting new additions	to each	and every version

       Richard M. Alderson III,	for writing the	`T in tcsh' section

Astron 6.17.00			 10 July 2009			       TCSH(1)

NAME | SYNOPSIS | DESCRIPTION | REFERENCE | ENVIRONMENT | FILES | NEW FEATURES (+) | BUGS | THE T IN TCSH | LIMITATIONS | SEE ALSO | VERSION | AUTHORS | THANKS TO

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